Balkan Wars

The background to the wars lies in the incomplete emergence of nation-states on the European territory of the Ottoman Empire during the second half of the 19th century. Serbia had gained substantial territory during the Russo-Turkish War, 1877–1878, while Greece acquired Thessaly in 1881 (although it lost a small area back to the Ottoman Empire in 1897) and Bulgaria (an autonomous principality since 1878) incorporated the formerly distinct province of Eastern Rumelia (1885). All three countries, as well as Montenegro, sought additional territories within the large Ottoman-ruled region known as Rumelia, comprising Eastern Rumelia, Albania, Macedonia, and Thrace.

The First Balkan War had some main causes, which included:^[4]

1. The Ottoman Empire was unable to reform itself, govern satisfactorily, or deal with the rising ethnic nationalism of its diverse peoples.
2. The Italo-Ottoman war of 1911 and the Albanian Revolts in the Albanian Provinces showed that the Empire was deeply "wounded" and unable to strike back against another war.
3. The Great Powers quarreled amongst themselves and failed to ensure that the Ottomans would carry out the needed reforms. This led the Balkan states to impose their own solution.
4. The Christian populations of the European part of the Ottoman Empire were oppressed by the Ottoman Reign, thus forcing the Christian Balkan states to take action.
5. Most importantly, the Balkan League was formed, and its members were confident that under those circumstances an organised and simultaneous declaration of war on the Ottoman Empire would be the only way to protect their compatriots and expand their territories in the Balkan Peninsula.

Throughout the 19th century, the Great Powers shared different aims over the "Eastern Question" and the integrity of the Ottoman Empire. Russia wanted access to the "warm waters" of the Mediterranean from the Black Sea; it pursued a pan-Slavic foreign policy and therefore supported Bulgaria and Serbia. Britain wished to deny Russia access to the "warm waters" and supported the integrity of the Ottoman Empire, although it also supported a limited expansion of Greece as a backup plan in case integrity of the Ottoman Empire was no longer possible. France wished to strengthen its position in the region, especially in the Levant (today's Lebanon, Syria, and Israel).^[5]

Habsburg-ruled Austria-Hungary wished for a continuation of the existence of the Ottoman Empire, since both were troubled multinational entities and thus the collapse of the one might weaken the other. The Habsburgs also saw a strong Ottoman presence in the area as a counterweight to the Serbian nationalistic call to their own Serb subjects in Bosnia, Vojvodina and other parts of the empire. Italy's primary aim at the time seems to have been the denial of access to the Adriatic Sea to another major sea power. The German Empire, in turn, under the "Drang nach Osten" policy, aspired to turn the Ottoman Empire into its own de facto colony, and thus supported its integrity. In the late 19th and early 20th century, Bulgaria and Greece contended for Ottoman Macedonia and Thrace. Ethnic Greeks sought the forced "Hellenization" of ethnic Bulgars, who sought "Bulgarization" of Greeks (Rise of nationalism). Both nations sent armed irregulars into Ottoman territory to protect and assist their ethnic kindred. From 1904, there was low-intensity warfare in Macedonia between the Greek and Bulgarian bands and the Ottoman army (the Struggle for Macedonia). After the Young Turk revolution of July 1908, the situation changed drastically.^[6]

The negotiation among the Balkan states' governments started in the latter part of 1911 and was all conducted in secret. The treaties and military conventions were published in French translations after the Balkan Wars on 24–26 of November in Le Matin, Paris, France ^[7] In April 1911, Greek PM Eleutherios Venizelos’ attempt to reach an agreement with the Bulgarian PM and form a defensive alliance against the Ottoman Empire was fruitless, because of the doubts the Bulgarians held on the strength of the Greek Army.^[7] Later that year, in December 1911, Bulgaria and Serbia agreed to start negotiations in forming an alliance under the tight inspection of Russia. The treaty between Serbia and Bulgaria was signed on 29 of February/13 of March 1912. Serbia sought expansion to "Old Serbia" and as Milan Milovanovich noted in 1909 to the Bulgarian counterpart, "As long as we are not allied with you, our influence over the Croats and Slovens will be insignificant". On the other side, Bulgaria wanted the autonomy of Macedonia region under the influence of the two countries. The then Bulgarian Minister of Foreign Affairs General Stefan Paprikov stated in 1909 that, "It will be clear that if not today then tomorrow, the most important issue will again be the Macedonian Question. And this question, whatever happens, cannot be decided without more or less direct participation of the Balkan States". Last but not least, they noted down the divisions that should be made of the Ottoman territories after a victorious outcome of the war. Bulgaria would gain all the territories eastern of Rodopi Mountains and River Strimona, while Serbia would annex the territories northern and western of Mount Skardu.

The alliance pact between Greece and Bulgaria was finally signed on 16/29 of May 1912, without stipulating any specific division of Ottoman territories.^[7] In summer 1912, Greece proceeded on making "gentlemen's agreements" with Serbia and Montenegro. Despite the fact that a draft of the alliance pact with Serbia was submitted on 22 of October, a formal pact was never signed due to the outbreak of the war. As a result, Greece did not have any territorial or other commitments, other than the common cause to fight the Ottoman Empire.

In April 1912 Montenegro and Bulgaria reached an agreement including financial aid to Montenegro in case of war with the Ottoman Empire. A gentlemen's agreement with Greece was reached soon after, as mentioned before. By the end of September a political and military alliance between Montenegro and Serbia was achieved.^[7] By the end of September 1912, Bulgaria had formal-written alliances with Serbia, Greece, and Montenegro. A formal alliance was also signed between Serbia and Montenegro, while Greco-Montenegrin and Greco-Serbian agreements were basically oral "gentlemen's agreements". All these completed the formation of the Balkan League.

The Albanian revolt of 1912, also known as the Albanian War of Independence, was the last revolt against the Ottoman Empire's rule in Albania and lasted from January until August 1912.^[100] The revolt ended when the Ottoman government agreed to fulfill the rebels' demands on 4 September 1912. Generally, Muslim Albanians fought against the Ottomans in the incoming Balkan War.

At that time, the Balkan states had been able to maintain armies that were both numerous, in relation to each country's population, and eager to act, being inspired by the idea that they would free enslaved parts of their homeland. The Bulgarian Army was the leading army of the coalition. It was a well-trained and fully equipped army, capable of facing the Imperial Army. It was suggested that the bulk of the Bulgarian Army would be in the Thracian front, as it was expected that the front near the Ottoman Capital would be the most crucial one. The Serbian Army would act on the Macedonian front, while the Greek Army was thought powerless and was not taken under serious consideration. Greece was needed in the Balkan League for its navy and its capability to dominate the Aegean Sea, cutting off the Ottoman Armies from reinforcements.

On 13/26 of September 1912, the Ottoman mobilization in Thrace forced Serbia and Bulgaria to act and order their own mobilization. On 17/30 of September Greece also ordered mobilization. On 25 of September/8 of October, Montenegro declared war on the Ottoman Empire, after negotiations failed regarding the border status. On 30 of September/13 of October, the ambassadors of Serbia, Bulgaria, and Greece delivered the common ultimatum to the Ottoman government, which was immediately rejected. The Empire withdrew its ambassadors from Sofia, Belgrade, and Athens, while the Bulgarian, Serbian and Greek diplomats left the Ottoman capital delivering the war declaration on 4/17 of October 1912.

The three Slavic allies (Bulgaria, Serbia, and Montenegro) had laid out extensive plans to coordinate their war efforts, in continuation of their secret prewar settlements and under close Russian supervision (Greece was not included). Serbia and Montenegro would attack in the theater of Sandjak, Bulgaria, and Serbia in Macedonia and Thrace.

The Ottoman Empire's situation was difficult. Its population of about 26 million people provided a massive pool of manpower, but three-quarters of the population lived in the Asian part of the Empire. Reinforcements had to come from Asia mainly by sea, which depended on the result of battles between the Turkish and Greek navies in the Aegean.

With the outbreak of the war, the Ottoman Empire activated three Army HQs: the Thracian HQ in Constantinople, the Western HQ in Salonika, and the Vardar HQ in Skopje, against the Bulgarians, the Greeks and the Serbians respectively. Most of their available forces were allocated to these fronts. Smaller independent units were allocated elsewhere, mostly around heavily fortified cities.

Montenegro was the first to declare war on 8 October.^[9] Its main thrust was towards Shkodra, with secondary operations in the Novi Pazar area. The rest of the Allies, after giving a common ultimatum, declared war a week later.

On the first day of the war, 18 October 1912, Delov's detachment advanced south across the border in four columns. The next day, they defeated the Ottoman troops at the villages of Kovancılar (present day: Pchelarovo) and Göklemezler (present day: Stremtsi) and then headed for Kardzhali. The detachment of Yaver Pasha left the town in disorder. With its advance towards Gumuljina, the Haskovo detachment threatened communications between the Ottoman armies in Thrace and Macedonia. For this reason, the Ottomans ordered Yaver Pasha to counter-attack before the Bulgarians could reach Kardzhali but did not send him reinforcements.^[17] To follow this order he had in command 9 tabors and 8 guns.^[16]

However, the Bulgarians were not aware of the strength of the enemy and on 19 October the Bulgarian High Command (the Headquarters of the Active Army under General Ivan Fichev) ordered General Ivanov to stop the advance of the Haskovo Detachment because it was considered risky. The commander of the 2nd Army, however, did not withdraw his orders and gave Delov freedom of action.^[15] The detachment continued with the advance on 20 October. The march was slowed by the torrential rains and the slow movement of the artillery but the Bulgarians reached the heights to the north of Kardzhali before the Ottomans could reorganize.^[18]

In the early morning of 21 October Yaver Pasha engaged the Bulgarians in the outskirts of the town. Due to their superior artillery and attacks on bayonet the soldiers of the Haskovo Detachment overran the Ottoman defenses and prevented their attempts to outflank them from the west. The Ottomans were in turn vulnerable to outflanking from the same direction and had to retreat for a second time to the south of the Arda River, leaving behind large quantities of munitions and equipment. At 16:00 the Bulgarians entered Kardzhali.^[19]

The Battle of Kircaali took place on 21 October 1912, when the Bulgarian Haskovo Detachment defeated the Ottoman Kırcaali Detachment of Yaver Pasha and permanently joined Kardzhali and the Eastern Rhodopes to Bulgaria. The defeated Ottomans retreated to Mestanlı while the Haskovo Detachment prepared defenses along the Arda. Thus the flank and the rear of the Bulgarian armies advancing towards Adrianople and Constantinople were secured.

The Battle of Kirk Kilisse took place on 24 October 1912, when the Bulgarian army defeated an Ottoman army in Eastern Thrace and occupied Kırklareli. The initial clashes were around several villages to the north of the town. The Bulgarian attacks were irresistible and the Ottoman forces were forced to retreat. On 10 October the Ottoman army threatened to split 1st and 3rd Bulgarian armies but it was quickly stopped by a charge by 1st Sofian and 2nd Preslav brigades. After bloody fighting along the whole town front the Ottomans began to pull back and on the next morning Kırk Kilise (Lozengrad) was in Bulgarian hands. The Muslim Turkish population of the town was expelled and fled eastwards towards Constantinople. After the victory, the French minister of war Alexandre Millerand stated that the Bulgarian Army was the best in Europe and that he would prefer 100,000 Bulgarians for allies than any other European army.^[26]

The Army of Epirus crossed the bridge of Arta into Ottoman territory at midday 6 October, capturing the Gribovo heights by the end of the day. On 9 October, the Ottomans counterattacked initiating the Battle of Gribovo, on the night of 10–11 October the Greeks were pushed back towards Arta. After regrouping the following day, the Greek army went on the offensive once again finding the Ottoman positions abandoned and capturing Filippiada. On 19 October, the Army of Epirus launched an attack on Preveza in conjunction with the Ionian squadron of the Greek Navy; taking the city on 21 October.^[20]

Following the fall of Preveza, Esad Pasha transferred his headquarters to the old Venetian castle at Pente Pigadia (Beshpinar). He ordered it to be repaired and augmented since it overlooked one of the two major roads leading to Yanya, while also recruiting local Cham Albanians into an armed militia.^[21] On 22 October, the 3rd Evzone Battalion and the 1st Mountain Battery entrenched themselves on Goura Height in the area of Anogeio. The 10th Evzone Battalions took up positions south east of Sklivani village (Kipos Height) and on Lakka Height in the vicinity of Pigadia village.^[22]

At 10:30 a.m. on 22 October, Ottoman artillery began bombarding the Greek positions while an Ottoman force consisting of five battalions deployed on the western Greek flank around Anogeio. Fierce clashes followed after a series of Ottoman assaults which reached their peak around midday. Hostilities ceased in the afternoon without any territorial changes, Greek casualties amounted to four killed and two wounded.^[22]

At 10:00 a.m. on 23 October, an Ottoman battalion coming from the direction of Aetorachi launched a surprise attack on Height 1495 of Briaskovo aiming to break into the rear of the Army of Epirus. The 1st and 3rd Companies of the 10th Evzone Battalion and the 2nd Company of the 3rd Evzone Battalion managed to hold their ground. They then forced the Ottomans to abandon their dead and wounded after launching a successful counter-attack. Ottoman attacks on Anogeio were likewise repulsed, while the Ottoman push on the eastern Greek flank was halted due to the harsh terrain in the area.^[23]

Early snowfall prevented the Ottomans from carrying out a large scale attack, while the Greeks held their ground in a series of clashes that lasted until 30 October.^[24] Upon halting their offensive the Ottomans withdrew to the village of Pesta.^[25] Greek casualties in the battle of Pente Pigadia numbered 26 dead and 222 wounded.^[24]

The Battle of Sarantaporo was the first major battle fought between Greek forces under Crown Prince Constantine and Ottoman forces under General Hasan Tahsin Pasha during the First Balkan War. The battle began when the Greek army attacked the Ottoman defensive line at the Sarantaporo pass, which connected Thessaly with central Macedonia.

Despite being perceived as impregnable by its defenders, the main body of the Greek forces managed to advance deep inside the pass, while auxiliary units broke through the Ottoman flanks. The Ottomans abandoned their defensive line during the night, fearing encirclement. The Greek victory at Sarantaporo opened the way for the capture of Servia and Kozani.

The Battle of Kumanovo was a major battle of the First Balkan War. It was an important Serbian victory over the Ottoman army in the Kosovo Vilayet, shortly after the outbreak of the war. After this defeat, the Ottoman army abandoned the major part of the region, suffering heavy losses in manpower (mostly due to desertions) and in war materiel.^[27]

The Ottoman Vardar Army fought the battle according to plan, but despite this, suffered a heavy defeat. Although Zeki Pasha operationally surprised the Serbian command by his sudden attack, the decision to act offensively against the superior enemy was a grave error which determined the outcome of Battle of Kumanovo.^[28] On the other side, the Serbian command started the battle without plans and preparations, and missed the chance to pursue the defeated enemy and effectively end the operations in the region, although it had the fresh troops of the rear echelon available for such action. Even after the end of battle, the Serbs still believed that it was fought against weaker Ottoman units and that main enemy forces were on Ovče Pole.^[28]

Nevertheless, the Battle of Kumanovo was a decisive factor in the outcome of the war in the region. The Ottoman plan for an offensive war had failed, and the Vardar Army was forced to abandon much territory and lost a significant number of artillery pieces without the possibility to reinforce, because the supply routes from Anatolia were cut.^[28]

The Vardar Army was not able to organise the defense on Vardar River and was forced to abandon Skopje, retreating all the way to Prilep. The First Army advanced slowly and entered Skopje on 26 October. Two days later, it was strengthened by Morava Division II, while the rest of the Third Army was sent to Western Kosovo and then through northern Albania to the Adriatic coast. The Second Army was sent to aid the Bulgarians in the Siege of Adrianople, while the First Army was preparing for an offense towards Prilep and Bitola.^[29]

The siege of Scutari was initiated by the Montenegrins on 28 October 1912. The initial attack was carried out by the Montenegrin army under the command of Prince Danilo and encountered stiff resistance. As the conflict settled into siege warfare, the Montenegrins were supported by reinforcements from their Serbian allies. Radomir Vešović, a Montenegrin army officer participated in the siege where he was wounded twice,^[30] for which he earned a golden Obilić Medal and the nickname the knight of Brdanjolt.

The Turkish and Albanian defenders of Scutari were led by Hasan Riza Pasha and his lieutenant, Essad Pasha. After the siege had continued for approximately three months, differences between the two Ottoman leaders boiled over on 30 January 1913, when Essad Pasha had two of his Albanian servants ambush and kill Riza Pasha.^[31] The ambush occurred as Riza Pasha left Essad's house after a dinner engagement and put Essad Pasha in total control of the Turkish forces at Scutari.^[32] Differences between the two men centered about the continued defense of the city. Riza Pasha desired to continue the fight against the Montenegrins and Serbs while Essad Pasha was a proponent of ending the siege by means of secret negotiations conducted with the counsel of the Russians. Essad Pasha's plan was to deliver Scutari to the Montenegrins and Serbs as the price for their support in his attempt to proclaim himself King of Albania.^[32]

The siege, however, continued and even escalated in February when King Nikola of Montenegro received a delegation of Malësian chieftains who stated their allegiance to him and volunteered to join the Montenegrin forces with 3,000 of their own soldiers. Shortly thereafter, the Malësian chieftains joined the war by assisting in the attack of the Jubani — Daut-age tower.^[33]

As Montengro continued their siege in April, the Great Powers decided to implement a blockade of their ports, which was declared on 10 April and lasted until 14 May 1913.^[34] On 21 April 1913 approximately six months after the start of the siege, Essad Pasha offered an official proposal to surrender the city to Montenegrin General Vukotic. On 23 April, Essad Pasha's proposal was accepted and he was allowed to leave the city with full military honors and all of his troops and equipment, except the heavy guns. He also received a sum of £10,000 sterling from the Montenegrin King.^[35]

Essad Pasha surrendered Scutari to Montenegro only after its destiny had been decided, meaning after the Great Powers had forced Serbia to retreat and after it was obvious that the Great Powers would not allow Montenegro to keep Scutari. At the same time, Essad Pasha managed to get the support of Serbia and Montenegro for the new Kingdom of Albania, which would gain Scutari indirectly by the Great Powers.^[36]

The capture of Scutari by Montenegro and Serbia removed the only obstacle to a Serbian advance into Ottoman Albania. By November 1912, Albania had declared independence but was yet to be recognized by anyone. The Serbian army eventually occupied most of northern and central Albania, stopping north of the town of Vlorë. The Serbians also managed to trap the remains of the Army of Vardar in what was left of Albania proper, but were unable to force them to surrender.^[37]

Following the quick Bulgarian victory on the Petra – Seliolu – Geckenli line and the capture of Kirk Kilisse (Kırklareli), the Ottoman forces retreated in disorder to the east and south. The Bulgarian Second Army under the command of gen. Nikola Ivanov besieged Adrianople (Edirne) but the First and Third armies failed to chase the retreating Ottoman forces. Thus the Ottomans were allowed to re-group and took new defensive positions along the Lule Burgas – Bunar Hisar line. The Bulgarian Third Army under gen. Radko Dimitriev reached the Ottoman lines on 28 October. The attack began the same day by the army's three divisions – 5th Danubian Infantry Division (commander major-gen. Pavel Hristov) on the left flank, 4th Preslav Infantry Division (major-gen. Kliment Boyadzhiev) in the centre and 6th Bdin Infantry Division (major-gen. Pravoslav Tenev) on the right flank. By the end of the day the 6th Division captured the town of Lule Burgas. With the arrival of the First Army on the battlefield the following day, attacks continued along the entire front line but were met with fierce resistance and even limited counter-attacks by the Ottomans. Heavy and bloody battles occurred on the next two days and the casualties were high on both sides. At the cost of heavy losses, the Bulgarian Fourth and 5th Division managed to push the Ottomans back and gained 5 km of land in their respective sectors of the frontline on 30 October.

The Bulgarians continued to push the Ottomans on the entire front. The 6th division managed to breach the Ottoman lines on the right flank. After another two days of fierce combat, the Ottoman defence collapsed and on the night of 2 November the Ottoman forces began a full retreat along the entire frontline. The Bulgarians again didn't immediately follow the retreating Ottoman forces and lost contact with them, which allowed the Ottoman army to take up positions on the Çatalca defence line just 30 km west of Constantinople. In terms of forces engaged it was the largest battle fought in Europe between the end of the Franco-Prussian War and the beginning of the First World War.

At 4 p.m. on 10 October, the 4th Division marched into Servia,^[10] while the Greek cavalry entered Kozani unopposed the following day.^[11] After their defeat at Sarantaporo, the Ottomans augmented the remnants of Hasan Tahsin Pasha's force with fresh reinforcements^[12] and organized their main defensive line at Yenidje (Giannitsa). On 18 October, Crown Prince Constantine ordered the bulk of the Army of Thessaly to head towards Yenidje despite receiving conflicting intelligence reports regarding the disposition of the enemy troops.^[13] In the meantime, the 5th Greek Division under Dimitrios Matthaiopoulos, continued its advance across western Macedonia, aiming to reach the Kailaria (Ptolemaida)-Perdika area, where it was to await further orders. There, the division would either unite with the rest of the Army of Thessaly or capture Monastir (Bitola). After crossing the Kirli Derven pass, it reached Banitsa (Vevi) on 19 October.^[14]

The 5th Greek Division continued its march through the Florina plain on 19 October, halting temporarily north of Kleidi Pass (Kirli Derven) after learning that the Ottomans were massing their troops at Florina, Armenochori and Neochori. The following day a Greek advanced guard repulsed an attack by a small Ottoman unit at Flampouro. On 21 October, Matthaiopoulos ordered an advance towards Monastir after being informed that it was guarded by a small demoralized garrison. This decision was further encouraged by the Serbian victory at Prilep and the Greek victory at Yenidje.^[15]

The Battle of Sorovich took place between 21–24 October 1912. It was fought between Greek and Ottoman forces during the First Balkan War, and revolved around the Sorovich (Amyntaio) area. The 5th Greek Division which had been advancing through western Macedonia separately from the bulk of the Greek Army of Thessaly, was attacked outside the village of Lofoi and fell back to Sorovich. It found itself to be heavily outnumbered by an opposing Ottoman force.

After withstanding repeated attacks between 22 and 23 October, the division was routed on the early morning of 24 October after Ottoman machine gunners struck its flank in an early morning surprise attack. The Greek defeat at Sorovich resulted in the Serbian capture of the contested city of Monastir (Bitola).

After their defeat at Sarandaporo, the Ottomans augmented the remnants of Hasan Tahsin Pasha's force with fresh reinforcements. Two divisions from east Macedonia, one reserve division from Asia Minor and one reserve division from Thessaloniki; bringing the total Ottoman forces in the area to 25,000 men and 36 artillery pieces.^[10] The Ottomans chose to organize their main defensive line at Yenidje either because of the town's religious importance for Macedonia's Muslim population or because they did not wish to fight too close to Thessaloniki.^[12] The Ottomans dug their trenches at a 130-meter (400 ft) high hill which overlooked the plain west of the town. The hill was surrounded by two rough streams, its southern approaches were covered by the swampy Giannitsa Lake while the slopes of Mount Paiko complicated any potential enveloping maneuver from the north.^[12] On the eastern approaches to Yenidje, the Ottomans reinforced the garrisons guarding the bridges across the Loudias River, the rail line at Platy and Gida.^[13]

On 18 October, the Greek general command ordered its troops forward despite receiving conflicting intelligence reports regarding the disposition of the enemy troops.^[11] The 2nd and 3rd Greek Divisions marched along the same route towards Tsaousli and Tsekre respectively, both located north-east of Yenidje. The 1st Greek Division acted as the army's rearguard. The 4th Division headed towards Yenidje from the north-west, while the 6th Division circumvented the city further to west, intending to capture Nedir. The 7th Division and the cavalry brigade covered the right flank of the army by advancing towards Gida; while the Konstantinopoulos Evzone detachment was ordered to seize Trikala.^[14]

The Battle of Yenidje began when the Greek army attacked the Ottoman fortified position at Yenidje (now Giannitsa, Greece), which was the last line of defense for the city of Thessaloniki.

The rough and swampy terrain surrounding Yenidje significantly complicated the advance of the Greek army, most notably its artillery. In the early morning of 20 October, an infantry charge by the Greek 9th Evzone Battalion caused the Greek army to gain momentum, leading to the collapse of the entire western wing of the Ottomans. Ottoman morale plunged and the bulk of the defenders began fleeing two hours later. The Greek victory at Yenidje opened the way for the capture of Thessaloniki and the surrender of its garrison, helping shape the modern map of Greece.

The Battle of Prilep in the First Balkan War took place on 3-5 November 1912 when the Serbian army encountered Ottoman troops near the town of Prilep, in today's North Macedonia. The clash lasted for three days. Eventually the Ottoman army was overwhelmed and forced to retreat.^[9]

Bad weather and difficult roads hampered the 1st Army’s pursuit of the Ottomans after the battle of Kumanovo, forcing the Morava Division to move ahead of the Drina Division. On 3 November, in the autumn rain, forward elements of the Morava Division encountered fire from Kara Said Pasha’s 5th Corps from positions north of Prilep. This started the three-day battle for Prilep, which was broken off that night and was renewed the next morning. When the Drina Division arrived on the battlefield, the Serbs gained an overwhelming advantage, forcing the Ottomans to withdraw south of the city.^[9]

On 5 November, as the Serbs moved south of Prilep they came again under Ottoman fire from prepared positions on the heights of the road to Bitola. Bayonets and hand grenades gave the Serbs the advantage in hand-to-hand fighting, but they still required the better part of the day to force the Ottomans to retreat. The overt and guileless nature of the Serbian infantry attacks impressed one Ottoman observer, who noted: "The development of the Serbian infantry attack was as open and clear as the execution of a barracks exercise. Large and strong units covered the entire plain. All the Serbian officers were seen clearly. They attacked as if on parade. The picture was very impressive. One part of the Turkish officers were struck dumb by the wonder of this mathematical disposition and order, the other sighed at this moment because of the absence of heavy artillery. They remarked on the arrogance of the open approach and clear frontal attack."^[9]

The artillery abandoned in Skoplje would have helped the Ottoman defenders south of Prilep. The Serbs demonstrated the same lack of subtlety in their infantry attacks that caused heavy casualties among all the combatants during the Balkan Wars and would cause many during the First World War. During this battle, the Serbian 1st Army was without the presence of its commanding general, Crown Prince Alexander. Ill from the rigors of the cold and wet campaign, he maintained telephone contact with his army from his sickbed in Skoplje.^[9]

The short, sharp battles around Prilep demonstrated that the Ottomans were still capable of opposing the Serbian march through Macedonia. Even after abandoning the city of Prilep, the Ottoman 5th Corps fought stubbornly south of town. The size and enthusiasm of the Serbs overcame the Ottomans, but at a cost. The Ottomans suffered around 300 dead and 900 wounded, and 152 were taken prisoner; the Serbs had losses of around 2,000 dead and wounded. The road southwest to Bitola now lay open to the Serbs.^[9]

The siege of Adrianople began on 3 November 1912 and ended on 26 March 1913 with the capture of Edirne (Adrianople) by the Bulgarian 2nd Army and the Serbian 2nd Army. The loss of Edirne delivered the final decisive blow to the Ottoman army and brought the First Balkan War to an end.^[44] A treaty was signed in London on 30 May. The city was reoccupied and retained by the Ottomans during the Second Balkan War.^[45]

The victorious end of the siege was considered to be an enormous military success because the city's defenses had been carefully developed by leading German siege experts and called 'undefeatable'. The Bulgarian army, after five months of siege and two bold night attacks, took the Ottoman stronghold.

The victors were under the overall command of Bulgarian General Nikola Ivanov while the commander of the Bulgarian forces on the eastern sector of the fortress was General Georgi Vazov, the brother of the famous Bulgarian writer Ivan Vazov and of General Vladimir Vazov.

The early use of an airplane for bombing took place during the siege; the Bulgarians dropped special hand grenades from one or more airplanes in an effort to cause panic among the Ottoman soldiers. Many young Bulgarian officers and professionals who took part in this decisive battle would later play important roles in Bulgarian politics, culture, commerce and industry.

On 8 November, Tahsin Pasha agreed to terms and 26,000 Ottoman troops passed over into Greek captivity. Before the Greeks entered the city, a German warship whisked the former sultan Abdul Hamid II out of Thessaloniki to continue his exile, across the Bosporus from Constantinople. With their army in Thessaloniki, the Greeks took new positions to the east and northeast, including Nigrita.

Upon learning of the outcome of the Battle of Giannitsa (Yenidje), the Bulgarian High Command urgently dispatched the 7th Rila Division from the north towards the city. The division arrived there a day later, the day after its surrender to the Greeks, who were further away from the city than the Bulgarians.

As an ongoing part of the Balkan Wars, the Ottoman Vardar Army retreated from the defeat at Kumanovo and regrouped around Bitola. The Serbs seized Skopje then sent forces to help their Bulgarian ally besiege Adrianople. The Serbian 1st Army, advancing south on Monastir (modern Bitola), encountered heavy Ottoman artillery fire and had to wait for its own artillery to arrive. According to French Captain G. Bellenger, writing in Notes on the Employment of Artillery in the Balkan Campaign, unlike the Ottomans, Serbian field artillery was very mobile, at some point the Serbian Morava Division dragged four long-range artillery pieces up a mountain, then each night hauled the guns closer to the Turkish forces to better support the infantry.^[46]

On 18 November, following the destruction of the Ottoman artillery by Serbian artillery, the Serbian right flank pushed through the Vardar Army. The Serbs then entered Bitola on 19 November. With the conquest of Bitola the Serbs controlled southwestern Macedonia, including the symbolically important town of Ohrid.^[47]

After the battle of Monastir, the five-century-long Ottoman rule of Macedonia was over. The Serbian 1st Army continued fighting in the First Balkan War. At this point some officers wanted the 1st Army to continue its advance down the valley of the Vardar to Thessaloniki. Vojvoda Putnik refused. The threat of war with Austria-Hungary loomed over the issue of a Serbian presence on the Adriatic. In addition, with the Bulgarians and Greeks already in Thessaloniki, the appearance of Serbian forces there would only muddle an already complicated situation.^[47]

The First Battle of Çatalca was one of the heaviest battles of the First Balkan War fought between 17 and 18 November 1912. It was initiated as an attempt of the combined Bulgarian First and Third armies, under the overall command of lieutenant general Radko Dimitriev, to defeat the Ottoman Çatalca Army and break through the last defensive line before the capital Constantinople. The high casualties however forced the Bulgarians to call off the attack.^[48]

During the First Balkan War (1912-1913), the Epirus front was of secondary importance for Greece after the Macedonian front.^[49] The landing in Himara, in the rear of the Ottoman Army was planned as an independent operation from the rest of the Epirus front. Its aim was to secure the advance of the Greek forces to the northern regions of Epirus. The success of such an initiative was primarily based on the superiority of the Greek navy in the Ionian Sea and the decisive support of the local Greek population.^[50] The Himara Revolt successfully overthrew the Ottoman forces of the region, thus securing the coastal area between Sarandë and Vlorë for the Hellenic Army.

The developments that led to the First Balkan War did not go unnoticed by the Great Powers. Although there was an official consensus between the European Powers over the territorial integrity of the Ottoman Empire, which led to a stern warning to the Balkan states, unofficially each of them took a different diplomatic approach due to their conflicting interests in the area.

Austria-Hungary, struggling for a port on the Adriatic and seeking ways for expansion in the south at the expense of the Ottoman Empire, was totally opposed to any other nation's expansion in the area. At the same time, the Habsburg empire had its own internal problems with significant Slav populations that campaigned against German-Hungarian control of the multinational state. Serbia, whose aspirations in the direction of Austrian-held Bosnia were no secret, was considered an enemy and the main tool of Russian machinations that were behind the agitation of Austria's Slav subjects. But Austria-Hungary failed to secure German backup for a firm reaction.

The Battle of Kaliakra, usually known as the Attack of the Drazki in Bulgaria, was a maritime action between four Bulgarian torpedo boats and the Ottoman cruiser Hamidiye in the Black Sea. It took place on 21 November 1912 at 32 miles off Bulgaria's primary port of Varna.

During the course of the First Balkan War, the Ottoman Empire's supplies were dangerously limited after the battles in Kirk Kilisse and Lule Burgas and the sea route from the Romanian port Constanţa to Istanbul became vital for the Ottomans. The Ottoman navy also imposed a blockade on the Bulgarian coast and on 15 October, the commander of the cruiser Hamidiye threatened to destroy Varna and Balchik, unless the two towns surrendered.

On 21 November an Ottoman convoy was attacked by the four Bulgarian torpedo boats Drazki (Bold), Letyashti (Flying), Smeli (Brave) and Strogi (Strict). The attack was led by Letyashti, whose torpedoes missed, as did those of Smeli and Strogi, Smeli being damaged by a 150 mm round with one of her crewmen wounded. Drazki however got within 100 meters from the Ottoman cruiser and her torpedoes struck the cruiser's starboard side, causing a 10 square meter hole.

However, Hamidiye was not sunk, due to her well-trained crew, strong forward bulkheads, the functionality of all her water pumps and a very calm sea. She did however have 8 crewmen killed and 30 wounded, and was repaired within months. After this encounter, the Ottoman blockade of the Bulgarian coast was significantly loosened.

With the outbreak of the First Balkan War in October 1912, the Greek fleet under Rear Admiral Pavlos Koundouriotis seized the strategic island of Lemnos at the entrance of the Dardanelles Straits, and proceeded to establish a naval blockade of the Straits. With the Ottoman fleet confined behind the Daradanelles, the Greeks were left with complete control of the Aegean Sea, and began occupying the Ottoman-ruled Aegean islands.^[51] Most of these islands had few or no troops, apart from the larger islands of Chios and Lesbos; the latter was garrisoned by the 2nd Battalion of the 18th Infantry Regiment.^[52] The Ottoman garrison numbered 3,600 men, of whom 1,600 were professional soldiers, with the rest being irregulars and drafted Christians, commanded by Major Abdul Ghani Pasha whose headquarters were based in Molyvos.^[53]

As a result, the Greeks delayed moving against Chios and Lesbos until operations were concluded on the main front in Macedonia and forces could be spared for a serious assault. With rumours of a cease-fire circulating in late November, the speedy capture of these islands became imperative. Another factor was Bulgaria's rapid advance in Thrace and eastern Macedonia. Τhe Greek government feared that Bulgaria may use Lesbos as a bargaining chip during the course of future peace negotiations.^[54] An ad hoc force was assembled for capturing Lesbos: naval infantry detachments were gathered at Mudros Bay and boarded on the cruiser Averoff and the steamer Pelops, along with some light naval artillery and two machine guns. Setting sail for Lesbos on 7 November 1912, the landing force were joined on the way by a newly raised reservist infantry battalion (15 officers and 1,019 men) from Athens.

The Battle of Lesbos took place from 21 November – 21 December 1912 during the First Balkan War, resulting in the capture of the eastern Aegean island of Lesbos by the Kingdom of Greece.

The occupation of the island was a prolonged affair. The Greek landing force, commanded by Colonel Nikolaos Delagrammatikas, was quickly able to seize the eastern coastal plain and the town of Chios, but the Ottoman garrison was well equipped and supplied, and managed to withdraw to the mountainous interior. A stalemate ensued, and operations almost ceased from the end of November and until the arrival of Greek reinforcements in late December. Finally, the Ottoman garrison was defeated and forced to surrender on 3 January 1913.^[55]

After a long chase throughout Western Thrace the Bulgarian troops led by General Nikola Genev and Colonel Aleksandar Tanev surrounded the 10,000-strong Kırcaali Detachment under the command of Mehmed Yaver Pasha.^[56] Attacked in the surrounding of the village Merhamli (Now Peplos in modern Greece), only a few of the Ottomans managed to cross the Maritsa River. The rest surrendered in the following day on 28 November.

With the capitulation at Merhamli the Ottoman Empire lost Western Thrace while the Bulgarian positions in the lower current of the Maritsa and around Istanbul stabilized. With their success the Mixed Cavalry Brigade and the Kardzhali Detachment secured the rear of the 2nd Army which was besieging Adrianople and eased the supplies for 1st and 3rd Armies at Chatalja.

The Albanian Declaration of Independence on November 28, 1912, had a significant impact on the First Balkan War, which was already underway at that time. The declaration of independence marked the emergence of Albania as a new state, which affected the balance of power in the Balkans and created new dynamics in the ongoing war.

The Kingdom of Serbia opposed the plan for this rather large Albanian state (whose territories are now considered to be the concept of Greater Albania), preferring a partition of the European territory of the Ottoman Empire among the four Balkan allies.

An armistice was agreed on 3 December 1912 between the Ottomans and Bulgaria, the latter also representing Serbia and Montenegro, and peace negotiations began in London. Greece also participated in the conference but refused to agree to a truce and continued its operations in the Epirus sector. The negotiations were interrupted on 23 January 1913, when a Young Turk coup d'état in Constantinople, under Enver Pasha, overthrew the government of Kâmil Pasha. Upon the expiration of the armistice, on 3 February 1913, hostilities restarted.

Since the start of the war the Hellenic Navy acted aggressively, while the Ottoman navy remained in the Dardanelles. Admiral Kountouriotis landed at Lemnos, while the Greek fleet liberated a series of islands. On 6 November, Kountouriotis sent a telegram to the Ottoman admiral: "We have captured Tenedos. We await the exit of your fleet. If you need coal, I can supply you." On 16 December, the Ottoman fleet left the Dardanelles.

The Royal Hellenic Navy, led by Rear Admiral Pavlos Kountouriotis on board of the flagship Averof, defeated the Ottoman Navy, led by Captain Ramiz Bey, just outside the entrance to the Dardanelles (Hellespont). During the battle, Kountouriotis, frustrated by the slow speed of the three older Greek battleships Hydra, Spetsai and Psara, hoisted the Z flag which stood for "Independent Action", and sailed forward alone at a speed of 20 knots, against the Ottoman fleet. Taking full advantage of her superior speed, guns and armour, Averof succeeded in crossing the Ottoman fleet's "T" and concentrated her fire against the Ottoman flagship Barbaros Hayreddin, thus forcing the Ottoman fleet to retreat in disorder. The Greek fleet, including the destroyers Aetos, Ierax and Panthir continued to pursue the Ottoman fleet off-and-on between the dates of December 13 and December 26, 1912.

This victory was quite significant in that the Ottoman navy retreated within the Straits and left the Aegean Sea to the Greeks who were now free to liberate the islands of Lesbos, Chios, Lemnos and Samos and others. It also prevented any transfer of Ottoman troop reinforcements by sea and effectively secured Ottoman defeat on land.

During the early stages of the war while the Balkan allies were victorious, the Hellenic Army liberated Thessaloniki and continued to advance west in Macedonia to Kastoria and then Korytsa.

The Epirus front was also active and the Ottoman forces under Djavid Pasha placed 24,000 Ottoman troops in Korytsa in order to protect north of Ioannina, the urban center of the Epirus region. On December 20, three days after peace negotiations started,^[57] the Greek forces pushed the Ottomans out of Korytsa.^[58]

This would give the Greek forces a significant advantage in controlling Ioannina and the entire area in March 1913 at the Battle of Bizani.

The Naval Battle of Lemnos was a naval battle during the First Balkan War, in which the Greeks defeated the second and last attempt of the Ottoman Empire to break the Greek naval blockade of the Dardanelles and reclaim supremacy over the Aegean Sea. This, the final naval battle of the First Balkan War, forced the Ottoman Navy to retreat to its base within the Dardanelles, from which it did not venture for the rest of the war, thus ensuring the dominion of the Aegean Sea and the Aegean islands by Greece.

The strong Ottoman fortress Edirne was blocked by the Bulgarian army since the beginning of the war in 1912. From the middle of January 1913 the Ottoman high command prepared an attack towards Edirne to break through the blockade.

The advance began in the morning of 8 February when the Myuretebi Division headed under the cover of fog from the Saor Bay toward the road to Bulair. The attack was uncovered at only 100 steps from the Bulgarian positions. In 7 o'clock the Ottoman artillery opened fire. The Bulgarian auxiliary artillery also opened fire, as did the soldiers of the 13th Infantry Regiment, and the enemy advance was slowed.

From 8 o'clock advanced the Ottoman 27th Infantry Division which concentrated on the shore-line of the Sea of Marmara. Due to their superiority the Ottomans seized the position at the Doganarslan Chiflik and began to surround the left wing of the 22nd Infantry Regiment. The command of the Seventh Rila Infantry Division reacted immediately and ordered a counter-attack of the 13th Rila Infantry Regiment, which forced the Myuretebi Division to pull back.

The Ottoman forces were surprised by the decisive actions of the Bulgarians and when they saw the advancing 22nd Thracian Infantry Regiment they panicked. The Bulgarian artillery now concentrated its fire on Doganarslan Chiflik. Around 15 o'clock 22nd Regiment counter-attacked the right wing of the Ottoman forces and after a short but fierce fight the enemy began to retreat. Many of the fleeing Ottoman troops were killed by the accurate fire of the Bulgarian artillery. After that the whole Bulgarian army attacked and defeated the Ottoman left wing.

Around 17 o'clock the Ottoman forces renewed the attack and headed towards the Bulgarian center but were repulsed and suffered heavy casualties. The position was cleared of Ottoman forces and the defensive line was reorganized. In the battle of Bulair the Ottoman forces lost almost half of their manpower and left all their equipment on the battlefield.

On 20 February, Ottoman forces began their attack, both in Çatalca and south of it, at Gallipoli. There, the Ottoman X Corps, with 19,858 men and 48 guns, landed at Şarköy while an attack of around 15,000 men supported by 36 guns (part of the 30,000-strong Ottoman army isolated in Gallipoli Peninsula) at Bulair, farther south. Both attacks were supported by fire from Ottoman warships and had been intended, in the long term, to relieve pressure on Edirne. Confronting them were about 10,000 men, with 78 guns.^[64] The Ottomans were probably unaware of the presence in the area of the new 4th Bulgarian Army, of 92,289 men, under General Stiliyan Kovachev. The Ottoman attack in the thin isthmus, with a front of just 1800m, was hampered by thick fog and the strong Bulgarian artillery and machine gunfire. As a result, the attack stalled and was repulsed by a Bulgarian counterattack. By the end of the day, both armies had returned to their original positions. Meanwhile, the Ottoman X Corps, which had landed at Şarköy, advanced until 23 February 1913, when the reinforcements that had been sent by General Kovachev succeeded in halting them.

Casualties on both sides were light. After the failure of the frontal attack in Bulair, the Ottoman forces at Şarköy re-entered their ships on 24 February and were transported to Gallipoli.

The Ottoman attack at Çatalca, directed against the powerful Bulgarian First and Third Armies, was initially launched only as a diversion from the Gallipoli-Şarköy operation to pin down the Bulgarian forces in situ. Nevertheless, it resulted in unexpected success. The Bulgarians, who were weakened by cholera and concerned that an Ottoman amphibious invasion might endanger their armies, deliberately withdrew about 15 km and to the south over 20 km to their secondary defensive positions, on higher ground to the west. With the end of the attack in Gallipoli, the Ottomans canceled the operation since they were reluctant to leave the Çatalca Line, but several days passed before the Bulgarians realized that the offensive had ended. By 15 February, the front had again stabilized, but fighting along the static lines continued. The battle, which resulted in heavy Bulgarian casualties, could be characterized as an Ottoman tactical victory, but it was a strategic failure since it did nothing to prevent the failure of the Gallipoli-Şarköy operation or to relieve the pressure on Edirne.

The Battle of Bizani was fought between Greek and Ottoman forces during the last stages of the First Balkan War, and revolved around the forts of Bizani, which covered the approaches to Ioannina, the largest city in the region.

At the outbreak of the war, the Hellenic Army on the Epirus front did not have the numbers to initiate an offensive against the German-designed defensive positions in Bizani. However, after the campaign in Macedonia was over, many Greek troops were redeployed to Epirus, where Crown Prince Constantine himself assumed command. In the battle that followed the Ottoman positions were breached and Ioannina taken. Despite having a slight numerical advantage, this was not the decisive factor in the Greek victory. Rather, "solid operational planning" by the Greeks was key as it helped them implement a well-coordinated and executed assault that did not allow the Ottoman forces time to react.^[59] Furthermore, the bombardment of Ottoman positions was the heaviest in world history up to that time.^[60] The surrender of Ioannina secured Greek control of southern Epirus and the Ionian coast. At the same time, it was denied to the newly formed Albanian state, for which it might have provided a southern anchor-point comparable to Shkodër in the north.

The failure of the Şarköy-Bulair operation and the deployment of the Second Serbian Army, with its much-needed heavy siege artillery, sealed Adrianople's fate. On 11 March, after a two weeks' bombardment, which destroyed many of the fortified structures around the city, the final assault started, with League forces enjoying a crushing superiority over the Ottoman garrison. The Bulgarian Second Army, with 106,425 men and two Serbian divisions with 47,275 men, conquered the city, with the Bulgarians suffering 8,093 and the Serbs 1,462 casualties.^[61] The Ottoman casualties for the entire Adrianople campaign reached 23,000 dead.^[62] The number of prisoners is less clear. The Ottoman Empire began the war with 61,250 men in the fortress.^[63] Richard Hall noted that 60,000 men were captured. Adding to the 33,000 killed, the modern "Turkish General Staff History" notes that 28,500-man survived captivity^[64] leaving 10,000 men unaccounted for^[63] as possibly captured (including the unspecified number of wounded). Bulgarian losses for the entire Adrianople campaign amounted to 7,682.^[65] That was the last and decisive battle that was necessary for a quick end to the war^[66] even though it is speculated that the fortress would have fallen eventually because of starvation. The most important result was that the Ottoman command had lost all hope of regaining the initiative, which made any more fighting pointless.^[67]

The battle had major and key results in Serbian-Bulgarian relations, planting the seeds of the two countries' confrontation some months later. The Bulgarian censor rigorously cut any references to Serbian participation in the operation in the telegrams of foreign correspondents. Public opinion in Sofia thus failed to realize the crucial services of Serbia in the battle. Accordingly, the Serbs claimed that their troops of the 20th Regiment were those who captured the Ottoman commander of the city and that Colonel Gavrilović was the allied commander who had accepted Shukri's official surrender of the garrison, a statement that the Bulgarians disputed. The Serbs officially protested and pointed out that although they had sent their troops to Adrianople to win for Bulgaria territory, whose acquisition had never been foreseen by their mutual treaty,^[68] the Bulgarians had never fulfilled the clause of the treaty for Bulgaria to send 100,000 men to help the Serbians on their Vardar Front. The friction escalated some weeks later, when the Bulgarian delegates in London bluntly warned the Serbs that they must not expect Bulgarian support for their Adriatic claims. The Serbs angrily replied that to be a clear withdrawal from the prewar agreement of mutual understanding, according to the Kriva Palanka-Adriatic line of expansion, but the Bulgarians insisted that in their view, the Vardar Macedonian part of the agreement remained active and the Serbs were still obliged to surrender the area, as had been agreed.^[68] The Serbs answered by accusing the Bulgarians of maximalism and pointed out that if they lost both northern Albania and Vardar Macedonia, their participation in the common war would have been virtually for nothing. The tension soon was expressed in a series of hostile incidents between both armies on their common line of occupation across the Vardar valley. The developments essentially ended the Serbian-Bulgarian alliance and made a future war between the two countries inevitable.

The Treaty of London ended the First Balkan War on 30 May 1913. All Ottoman territory west of the Enez-Kıyıköy line was ceded to the Balkan League, according to the status quo at the time of the armistice. The treaty also declared Albania to be an independent state. Almost all of the territory that was designated to form the new Albanian state was currently occupied by either Serbia or Greece, which only reluctantly withdrew their troops. Having unresolved disputes with Serbia over the division of northern Macedonia and with Greece over southern Macedonia, Bulgaria was prepared, if the need arose, to solve the problems by force, and began transferring its forces from Eastern Thrace to the disputed regions. Unwilling to yield to any pressure Greece and Serbia settled their mutual differences and signed a military alliance directed against Bulgaria on 1 May 1913, even before the Treaty of London had been concluded. This was soon followed by a treaty of "mutual friendship and protection" on 19 May/1 June 1913. Thus the scene for the Second Balkan War was set.

On June 1, 1913, two days after the signing of the Treaty of London and just 28 days before the Bulgarian attack, Greece and Serbia signed a secret defensive alliance, confirming the current demarcation line between the two occupation zones as their mutual border and concluding an alliance in case of an attack from Bulgaria or from Austria-Hungary. With this agreement, Serbia succeeded in making Greece a part of its dispute over northern Macedonia, since Greece had guaranteed Serbia's current (and disputed) occupation zone in Macedonia.^[69] In an attempt to halt the Serbo-Greek rapprochement, Bulgarian Prime Minister Geshov signed a protocol with Greece on 21 May agreeing on a permanent demarcation between their respective forces, effectively accepting Greek control over southern Macedonia. However, his later dismissal put an end to the diplomatic targeting of Serbia.

Another point of friction arose: Bulgaria's refusal to cede the fortress of Silistra to Romania. When Romania demanded its cession after the First Balkan War, Bulgaria's foreign minister offered instead some minor border changes, which excluded Silistra, and assurances for the rights of the Kutzovlachs in Macedonia. Romania threatened to occupy Bulgarian territory by force, but a Russian proposal for arbitration prevented hostilities. In the resulting Protocol of St. Petersburg of 9 May 1913, Bulgaria agreed to give up Silistra. The resulting agreement was a compromise between the Romanian demands for the city, two triangles at the Bulgaria–Romania border and the city of Balchik and the land between it and Romania and the Bulgarian refusal to accept any cession of its territory. However the fact that Russia failed to protect the territorial integrity of Bulgaria made the Bulgarians uncertain of the reliability of the expected Russian arbitration of the dispute with Serbia.^[70] The Bulgarian behavior had also a long-term impact on the Russo-Bulgarian relations. The uncompromising Bulgarian position tο review the pre-war agreement with Serbia during a second Russian initiative for arbitration between them finally led Russia to cancel its alliance with Bulgaria. Both acts made conflict with Romania and Serbia inevitable.

As skirmishing continued in Macedonia, mainly between Serbian and Bulgarian troops, Tsar Nicholas II of Russia tried to stop the upcoming conflict, since Russia did not wish to lose either of its Slavic allies in the Balkans. On 8 June, he sent an identical personal message to the Kings of Bulgaria and Serbia, offering to act as arbitrator according to the provisions of the 1912 Serbo-Bulgarian treaty. Serbia was asking for a revision of the original treaty, since it had already lost north Albania due to the Great Powers' decision to establish the state of Albania, an area that had been recognized as a Serbian territory of expansion under the prewar Serbo-Bulgarian treaty, in exchange for the Bulgarian territory of expansion in northern Macedonia. The Bulgarian reply to the Russian invitation contained so many conditions that it amounted to an ultimatum, leading Russian diplomats to realize that the Bulgarians had already decided to go to war with Serbia. That caused Russia to cancel the arbitration initiative and to angrily repudiate its 1902 treaty of alliance with Bulgaria. Bulgaria was shattering the Balkan League, Russia's best defense against Austrian–Hungarian expansionism, a structure that had cost Russia much blood, money and diplomatic capital during the last 35 years.^[71] Russia's Foreign Minister Sazonov's exact words to Bulgaria's new Prime Minister Stoyan Danev were "Do not expect anything from us, and forget the existence of any of our agreements from 1902 until present."^[72] Tsar Nicholas II of Russia was already angry with Bulgaria because of the latter's refusal to honor its recently signed agreement with Romania over Silistra, which had been the result of Russian arbitration. Then Serbia and Greece proposed that each of the three countries reduce its army by one fourth, as a first step to facilitate a peaceful solution, but Bulgaria rejected it.

The Second Balkan War broke out when Bulgaria, dissatisfied with its share of the spoils of the First Balkan War, attacked its former allies, Serbia and Greece. Serbian and Greek armies repulsed the Bulgarian offensive and counter-attacked, entering Bulgaria. With Bulgaria also having previously engaged in territorial disputes with Romania and the bulk of Bulgarian forces engaged in the south, the prospect of an easy victory incited Romanian intervention against Bulgaria. The Ottoman Empire also took advantage of the situation to regain some lost territories from the previous war.

The Battle of Bregalnitsa is a collective name for the fighting between Serbian and Bulgarian troops along the middle course of the Vardar , the stretch of the Bregalnitsa River and the slopes of the Osogovo Mountain between June 30 - July 9 1913, which ended with a retreat of the Bulgarians to the village of Tsarevo.

During the night of 16–17 June, the Bulgarians, without an official declaration of war, attacked their former Greek and the Serbian allies, and managed to evict the Serbs from Gevgelija, cutting off communication between them and the Greeks. However, the Bulgarians failed to drive the Serbs away from the Vardar/Axios river line. After repulsing the initial Bulgarian attack of 17 June, the Greek army, under King Constantine, advanced with 8 divisions and a cavalry brigade, while the Bulgarians under General Ivanov retreated to the naturally strong defensive position of the Kilkis–Lachanas line.

At Kilkis, the Bulgarians had constructed strong defenses including captured Ottoman guns which dominated the plain below. The Greek divisions attacked across the plain in rushes under Bulgarian artillery fire. On 19 June, the Greeks overran the Bulgarian forward lines everywhere but suffered heavy losses as the Bulgarian artillery fired incessantly with great accuracy guided by their observation on the hills of Kilkis. Acting under the previous order of the Greek HQ which requested Kilkis be captured by the night of 20 June, the 2nd division went forward alone. During the night of 20 June, following an artillery fire exchange, two regiments of the 2nd division crossed the Gallikos River and successively attacked the 1st, 2nd and 3rd defensive lines of the Bulgarians entering the town of Kilkis by the morning of 21 June. In the morning the rest of the Greek divisions joined the attack and the Bulgarians retreated to the north. The Greeks pursued the retreating Bulgarians but lost contact with their enemy due to exhaustion. 

The defeat of the Bulgarian 2nd Army by the Greeks was the greatest military disaster suffered by the Bulgarians in the 2nd Balkan war. On the Bulgarian right, the Evzones captured Gevgelija and the heights of Matsikovo. As a consequence, the Bulgarian line of retreat through Doiran was threatened and Ivanov's army began a desperate retreat which at times threatened to become a rout. Reinforcements came too late and joined the retreat toward Strumica and the Bulgarian border. The Greeks captured Dojran on 5 July but were unable to cut off the Bulgarian retreat through Struma Pass. On 11 July, the Greeks came in contact with the Serbs and then pushed on up the Struma River until they reached Kresna Gorge on 24 July.

The Battle of Knjaževac was a battle of the Second Balkan War, fought between the Bulgarian and the Serbian army. The battle took in July 1913 and ended with the capture of the Serbian city by the Bulgarian 1st Army.

Romania mobilised its army on 5 July 1913, with the intention of seizing Southern Dobruja, and declared war on Bulgaria on 10 July 1913. In a diplomatic circular that said, "Romania does not intend either to subjugate the polity nor defeat the army of Bulgaria", the Romanian government endeavoured to allay international concerns about its motives and increased bloodshed.^[73]

The Southern Dobruja Offensive was the opening action of the Romanian invasion of Bulgaria during the Second Balkan War of 1913. Aside from Southern Dobruja itself, Varna was also briefly occupied by Romanian cavalry, until it became apparent that no Bulgarian resistance would be offered. Southern Dobruja was subsequently annexed by Romania.

At the war's start, the Bulgarian First Army was situated in north-western Bulgaria. Its advance into Serbian territory was successful between 22 and 25 June, but Romania's unexpected intervention in the war and the Bulgarian Army's retreat from the front against Greece forced the Bulgarian chief of staff to transfer most of the country's troops into the region of Macedonia.^[76] During the retreat via the city of Ferdinand (now Montana), a large part of the 9th infantry division mutinied and surrendered to the Romanians on 5 July.^[77] Consequently only a small, mostly militia force remained to face the Serbian counteroffensive in the areas of Belogradchik and Vidin.

On 8 July, the garrison of Belogradchik was overrun by the advancing Serbs of the Timok group and a small portion of Bulgarian soldiers who had survived the Serb onslaught retreated to Vidin. The next day, the Serbs entered Belogradchik while their cavalry blocked the land connection to Vidin from the rest of Bulgaria.

On 14 July, the Serbs started to bombard the ramparts and the city itself. The Bulgarian commander, General Krastyu Marinov, refused to surrender twice. The relentless bombardment continued for three straight days, causing insignificant military casualties for the Bulgarian side.^[78] In the late afternoon of 17 July, after a lengthy artillery bombardment, a Serbian infantry division attacked the western sector of Vidin, located between the villages of Novoseltsi and Smardan. Two Serbian attacks had been repulsed by the Bulgarians by that evening. On 18 July, the Serbs notified General Marinov of the armistice that had been signed on the same day in Bucharest. Afterwards, the Serbians retreated from the region.^[78]

On 13 July 1913, General Mihail Savov assumed control of the 4th and 5th Bulgarian armies.^[74] The Bulgarians then entrenched themselves into strong defensive-positions around the village of Kalimanci, near the Bregalnica River in the northeastern part of Macedonia.^[74]

On 18 July, the Serbian 3rd Army attacked, closing in on the Bulgarian positions.^[74] The Serbs threw hand grenades at their enemies in an attempt to dislodge the Bulgarians, who were sheltered 40 feet away.^[74] The Bulgarians held firm, and on several occasions they allowed the Serbs to advance. When the Serbs were within 200 yards of their trenches, they charged with fixed bayonets and threw them back.^[74] The Bulgarian artillery was also very successful in breaking up the Serb attacks.^[74] The Bulgarian lines held, an invasion of their homeland was repelled, and their morale grew substantially.^[74]

If the Serbs had broken through the Bulgarian defences, they might have doomed the 2nd Bulgarian Army and driven the Bulgarians entirely out of Macedonia.^[74] This defensive victory, along with the successes of the 1st and 3rd armies in the north, protected western Bulgaria from a Serbian invasion.^[75] Although this victory boosted the Bulgarians, the situation was critical in the south, with the Greek Army defeating the Bulgarians in numerous skirmishes.^[75]

The lack of resistance to the Romanian invasion convinced the Ottomans to invade the territories just ceded to Bulgaria. The main object of the invasion was the recovery of Edirne (Adrianople), which was held by Major General Vulko Velchev with a mere 4,000 troops.^[98] The majority of Bulgarian forces occupying East Thrace had been withdrawn earlier in the year to face the Serbo-Greek attack. On 12 July, Ottoman troops garrisoning Çatalca and Gelibolu reached the Enos–Midia line and on 20 July 1913 crossed the line and invaded Bulgaria.^[98] The entire Ottoman invasion force contained between 200,000 and 250,000 men under the command of Ahmed Izzet Pasha. The 1st Army was stationed at the eastern (Midia) end of the line. From east to west it was followed by the 2nd Army, 3rd Army and 4th Army, which was stationed at Gelibolu.^[98]

In the face of the advancing Ottomans, the greatly outnumbered Bulgarian forces retreated to the pre-war border. Edirne was abandoned on 19 July, but when the Ottomans did not occupy it immediately the Bulgarians re-occupied it the next day (20 July). Since it was apparent that the Ottomans were not stopping, it was abandoned a second time on 21 July and occupied by the Ottomans on 23 July.^[98]

The Ottoman armies did not stop at the old border, but crossed into Bulgarian territory. A cavalry unit advanced on Yambol and captured it on 25 July.^[98] The Ottoman invasion, more than the Romanian, incited panic among the peasantry, many of whom fled to the mountains. Among the leadership it was recognized as a complete reversal of fortune. Like the Romanians, the Ottomans suffered no combat casualties, but lost 4,000 soldiers to cholera.^[98] Some 8000 Armenians fighting for the Ottomans were wounded. The sacrifice of these Armenians was praised greatly in Turkish papers.^[99]

To help Bulgaria repulse the rapid Ottoman advance in Thrace, Russia threatened to attack the Ottoman Empire through the Caucasus, and send its Black Sea Fleet to Constantinople; this caused Britain to intervene.

Greek advance and breaking through the Kresna Pass

After the victorious Battle of Doiran the Greek forces continued their advances north. On 18 July, the 1st Greek Division managed to drive back the Bulgarian rear guard and captured an important foothold at the southern end of the Kresna Pass.^[80]

In the pass, the Greeks were ambushed by the Bulgarian 2nd and 4th Armies which were newly arrived from the Serbian front and had taken up defensive positions. After bitter fighting, however, the Greeks managed to break through the Kresna Pass. The Greek advance continued and on 25 July, the village of Krupnik, north of the pass, was captured, forcing the Bulgarian troops to withdraw to Simitli.^[81] Simitli was captured on 26 July,^[82] while during the night of 27–28 July the Bulgarian forces were pushed north to Gorna Dzhumaya (now Blagoevgrad), 76 km south of Sofia.^[83]

Meanwhile, the Greek forces continued their march inland into Western Thrace and on 26 July, entered Xanthi. The next day the Greek forces entered Komotini, without incurring Bulgarian opposition.^[83]

Bulgarian counterattack and armistice

The Greek army was stopped in front of Gorna Dzhumaya by significant Bulgarian resistance.^[84] On 28 July, Greek forces resumed the attack and captured a line stretching from Cherovo to Hill 1378, southeast of Gorna Dzhumaya.^[85] During the evening of 28 July, however, the Bulgarian army under heavy pressure was forced to abandon the town.^[86]

The following day, the Bulgarians attempted to encircle the outnumbered Greeks in a Cannae-type battle by applying pressure on their flanks.^[87] Nevertheless, the Greeks launched counterattacks at Mehomia and to the west of Kresna. By 30 July, the Bulgarian attacks had largely subsided. On the eastern flank, the Greek army launched an attack towards Mehomia through the Predela Pass. The offensive was stopped by the Bulgarian army on the eastern side of the pass and fighting ground to a stalemate. On the western flank, an offensive was launched against Charevo Selo with the objection of reaching the Serbian lines. This failed and the Bulgarian army continued advancing, especially in the south, where by 29 July the Bulgarian forces had cut the Greek line of retreat through Berovo and Strumica, leaving the Greek army with only one route of retreat.^[88]

After three days fighting at the sectors of Pehčevo and Mehomia, however, the Greek forces retained their positions.^[85] On 30 July, the Greek headquarters planned to launch a new attack in order to advance towards the sector of Gorna Dzhumaya.^[89] On that day hostilities continued with the Bulgarian forces deployed on strategic positions north and northeast of the town.

Meanwhile, King Constantine I, who had neglected a Bulgarian request for truce during the drive for Sofia, informed Prime Minister Venizelos, that his army was "physically and morally exhausted" and urged him to seek cessation of hostilities^[87] through Romanian mediation. This request resulted in the Treaty of Bucharest being signed on 31 July 1913 which ended one of the bloodiest battles of the Second Balkan War.

Armistice

With the Romanian army closing in on Sofia, Bulgaria asked Russia to arbitrate. On 13 July, Prime Minister Stoyan Danev resigned in the face of Russian inactivity. On 17 July the tsar appointed Vasil Radoslavov to head a pro-German and Russophobic government.^[74] On 20 July, via Saint Petersburg, the Serbian Prime Minister Nikola Pašić invited a Bulgarian delegation to treat with the allies directly at Niš in Serbia. The Serbs and Greeks, both now on the offensive, were in no rush to conclude a peace. On 22 July, Tsar Ferdinand sent a message to King Carol via the Italian ambassador in Bucharest. The Romanian armies halted before Sofia.^[74] Romania proposed that talks be moved to Bucharest, and the delegations took a train from Niš to Bucharest on 24 July.^[74]

When the delegations met in Bucharest on 30 July, the Serbs were led by Pašić, the Montenegrins by Vukotić, the Greeks by Venizelos, the Romanians by Titu Maiorescu and the Bulgarians by Finance Minister Dimitur Tonchev. They agreed to a five-day armistice to come into effect on 31 July.^[90] Romania refused to allow the Ottomans to participate, forcing Bulgaria to negotiate with them separately.^[90]

Treaty of Bucharest

Bulgaria had agreed to cede Southern Dobruja to Romania as early as 19 July. At the peace talks in Bucharest, the Romanians, having obtained their primary objective, were a voice for moderation.^[90] The Bulgarians hoped to keep the Vardar river as the boundary between their share of Macedonia and Serbia's. The latter preferred to keep all of Macedonia as far as the Struma. Austro-Hungarian and Russian pressure forced Serbia to be satisfied with most of northern Macedonia, conceding only the town of Štip to the Bulgarians, in Pašić's words, "in honour of General Fichev", who had brought Bulgarian arms to the door of Constantinople in the first war.^[90] Ivan Fichev was chief of the Bulgarian general staff and a member of the delegation in Bucharest at the time. Although Austria-Hungary and Russia supported Bulgaria, the influential alliance of Germany—whose Kaiser Wilhelm II was brother-in-law to the Greek king—and France secured Kavala for Greece.

The last day of negotiations was 8 August. On 10 August Bulgaria, Greece, Montenegro, Romania and Serbia signed the Treaty of Bucharest and divided Macedonia in three: Vardar Macedonia went to Serbia; the smallest part, Pirin Macedonia, to Bulgaria; and the coastal and largest part, Aegean Macedonia, to Greece.^[90] Bulgaria thus enlarged its territory by 16 percent compared to what it was before the First Balkan War, and increased its population from 4.3 to 4.7 million people. Romania enlarged her territory by 5 percent and Montenegro by 62 percent.^[91] Greece increased her population from 2.7 to 4.4 million and her territory by 68 percent. Serbia almost doubled her territory enlarging her population from 2.9 to 4.5 million.^[92]

In August, Ottoman forces established a provisional government of Western Thrace at Komotini to pressure Bulgaria to make peace. Bulgaria sent a three-man delegation — General Mihail Savov and the diplomats Andrei Toshev and Grigor Nachovich — to Constantinople to negotiate a peace on 6 September.^[92] The Ottoman delegation was led by Foreign Minister Mehmed Talat Bey, assisted by future Naval Minister Çürüksulu Mahmud Pasha and Halil Bey.

Resigned to losing Edirne, the Bulgarians played for Kırk Kilise (Lozengrad in Bulgarian). Bulgarian forces finally returned south of the Rhodopes in October. The Radoslavov government continued to negotiate with the Ottomans in the hopes of forming an alliance. These talks finally bore fruit in the Secret Bulgarian–Ottoman Treaty of August 1914.

As part of the Treaty of Constantinople, 46,764 Orthodox Bulgarians from Ottoman Thrace were exchanged for 48,570 Muslims (Turks, Pomaks, and Roma) from Bulgarian Thrace.^[94] After the exchange, according to the 1914 Ottoman census, there still remained 14,908 Bulgarians belonging to the Bulgarian Exarchate in Ottoman Empire.^[95]

On 14 November 1913 Greece and the Ottomans signed a treaty in Athens bringing to a formal end the hostilities between them. On 14 March 1914, Serbia signed a treaty in Constantinople, restoring relations with the Ottoman Empire and reaffirming the 1913 Treaty of London.^[92] No treaty between Montenegro and the Ottoman Empire was ever signed.

The Second Balkan War left Serbia as the most militarily powerful state south of the Danube.^[96] Years of military investment financed by French loans had borne fruit. Central Vardar and the eastern half of the Sanjak of Novi Pazar were acquired. Its territory grew in extent from 18,650 to 33,891 square miles and its population grew by more than one and a half million. The aftermath brought harassment and oppression for many in the newly conquered lands. The freedom of association, assembly and the press guaranteed under the Serbian constitution of 1903 were not introduced into the new territories. The inhabitants of the new territories were denied voting rights, ostensibly because the cultural level was considered too low, in reality to keep the non-Serbs who made up the majority in many areas out of national politics. There was a destruction of Turkish buildings, schools, baths, mosques. In October and November 1913 British vice-consuls reported systematic intimidation, arbitrary detentions, beatings, rapes, village burnings and massacres by Serbs in the annexed areas. The Serbian government showed no interest in preventing further outrages or investigating those that had taken place. ^[97]

The treaties forced the Greek Army to evacuate Western Thrace and Pirin Macedonia, which it had occupied during operations. The retreat from the areas that had to be ceded to Bulgaria, together with the loss of Northern Epirus to Albania, was not well received in Greece; from the areas occupied during the war, Greece succeeded in gaining only the territories of Serres and Kavala after diplomatic support from Germany. Serbia made additional gains in northern Macedonia and having fulfilled its aspirations to the south, turned its attention to the north where its rivalry with Austro-Hungary over Bosnia-Herzegovina led the two countries to war a year later igniting the First World War. Italy used the excuse of the Balkan wars to keep the Dodecanese islands in the Aegean which it had occupied during the Italo-Turkish War of 1911 over Libya, despite the agreement that ended that war in 1912.

At the strong insistence of Austria-Hungary and Italy, both hoping to control for themselves the state and thus the Otranto Straits in Adriatic, Albania acquired officially its independence according to the terms of the Treaty of London. With the delineation of the exact boundaries of the new state under the Protocol of Florence (17 December 1913), the Serbs lost their outlet to the Adriatic and the Greeks the region of Northern Epirus (Southern Albania).

After its defeat, Bulgaria turned into a revanchist local power looking for a second opportunity to fulfill its national aspirations. To this end, it participated in the First World War on the side of the Central Powers, since its Balkan enemies (Serbia, Montenegro, Greece, and Romania) were pro-Entente. The resulting enormous sacrifices during World War I and renewed defeat caused Bulgaria a national trauma and new territorial losses.