Byzantine Empire: Justinian dynasty

The Justinian Dynasty began with the accession of its namesake Justin I to the throne. Justin I was born in a small village, Bederiana, in the 450s CE. Like many country youths, he went to Constantinople and enlisted in the army, where, due to his physical abilities, he became a part of the Excubitors, the palace guards. He fought in the Isaurian and Persian wars, and rose through the ranks to become the commander of the Excubitors, which was a very influential position. In this time, he also achieved the rank of senator. After the death of the Emperor Anastasius, who had left no clear heir, there was much dispute as to who would become emperor. To decide who would ascend the throne, a grand meeting was called in the hippodrome. The Byzantine Senate, meanwhile, gathered in the great hall of the palace. As the senate wanted to avoid outside involvement and influence, they were pressed to quickly select a candidate; however, they could not agree. Several candidates were nominated, but were rejected for various reasons. After much arguing, the senate chose to nominate Justin; and he was crowned by the Patriarch of Constantinople John of Cappadocia on 10 July.

Justin I's reign is significant for the founding of the Justinian dynasty that included his eminent nephew Justinian I and three succeeding emperors. His consort was Empress Euphemia. He was noted for his strongly orthodox Christian views. This facilitated the ending of the Acacian schism between the churches of Rome and Constantinople, resulting in good relations between Justin and the papacy. Throughout his reign he stressed the religious nature of his office and passed edicts against various Christian groups seen at the time as non-Orthodox. In foreign affairs he used religion as an instrument of state. He endeavoured to cultivate client states on the borders of the Empire, and avoided any significant warfare until late in his reign.

Unlike most emperors before him, who were Monophysite, Justin was a devout Orthodox Christian. Monophysites and the Orthodox were in conflict over the dual natures of Christ. Past emperors had supported the Monophysites' position, which was in direct conflict with the Orthodox teachings of the Papacy, and this strife led to the Acacian Schism. Justin, as an Orthodox, and the new patriarch, John of Cappadocia, immediately set about repairing relations with Rome. After delicate negotiations, the Acacian Schism ended in late March, 519.

Lazica was a border state of the Byzantine Empire and the Sassanid Empire; it was Christian, but in the Sassanid sphere. It's king, Tzath, wished to reduce Sassanid influence. In 521 or 522, he went to Constantinople to receive the insignia and royal robes of kingship from Justin's hand and to make his submission. He was also baptized as a Christian and married a Byzantine noblewoman, Valeriana. After having been confirmed in his kingdom by the Byzantine emperor, he returned to Lazica. Shortly after Justin's death the Sassanids attempted to forcibly regain control, but were beaten off with assistance from Justin's successor.

Kaleb I of Aksum was probably encouraged to aggressively enlarge his empire by Justin. Contemporary chronicler John Malalas reported that Byzantine merchants were robbed and killed by the Jewish King of the south Arabian Kingdom of Himyar, causing Kaleb to claim, "You have acted badly because you have killed merchants of the Christian Romans, which is a loss both to myself and my kingdom." Himyar was a client state of the Sassanian Persians, perennial enemies of the Byzantines. Kaleb invaded Himyar, vowing to convert to Christianity if successful, which he was in 523. Justin thus saw what is now Yemen pass from Sassanian control to that of an allied and Christian state.

Antioch was destroyed by an earthquake with an estimated 250,000 deaths. Justin arranged for sufficient money to be sent to the city for both immediate relief and to start reconstruction.

The Iberian War was fought from 526 to 532 between the Byzantine Empire and the Sasanian Empire over the eastern Georgian kingdom of Iberia—a Sasanian client state that defected to the Byzantines. Conflict erupted among tensions over tribute and the spice trade. The Sasanians maintained the upper hand until 530 but the Byzantines recovered their position in battles at Dara and Satala while their Ghassanid allies defeated the Sasanian-aligned Lakhmids.

Justinian's reign is marked by the ambitious "restoration of the Empire". This ambition was expressed by the partial recovery of the territories of the defunct Western Roman Empire. His general, Belisarius, swiftly conquered the Vandal Kingdom in North Africa. Subsequently, Belisarius, Narses, and other generals conquered the Ostrogothic kingdom, restoring Dalmatia, Sicily, Italy, and Rome to the empire after more than half a century of rule by the Ostrogoths. The praetorian prefect Liberius reclaimed the south of the Iberian peninsula, establishing the province of Spania. These campaigns re-established Roman control over the western Mediterranean, increasing the Empire's annual revenue by over a million solidi. During his reign, Justinian also subdued the Tzani, a people on the east coast of the Black Sea that had never been under Roman rule before. He engaged the Sasanian Empire in the east during Kavad I's reign, and later again during Khosrow I's; this second conflict was partially initiated due to his ambitions in the west.

A still more resonant aspect of his legacy was the uniform rewriting of Roman law, the Corpus Juris Civilis, which is still the basis of civil law in many modern states. His reign also marked a blossoming of Byzantine culture, and his building program yielded works such as the Hagia Sophia. He is called "Saint Justinian the Emperor" in the Eastern Orthodox Church. Because of his restoration activities, Justinian has sometimes been known as the "Last Roman" in mid-20th century historiography.

Shortly after Justinian became emperor in 527, he decided the empire's legal system needed repair. There existed three codices of imperial laws and other individual laws, many of which conflicted or were out of date. In February 528, Justinian created a ten-man commission to review these earlier compilations as well as individual laws, eliminate everything unnecessary or obsolete, make changes as it saw fit, and create a single compilation of imperial laws in force.

The Codex consists of twelve books: book 1 concerns ecclesiastical law, sources of law, and the duties of higher offices; books 2–8 cover private law; book 9 deals with crimes; and books 10–12 contain administrative law. The Code's structure is based on ancient classifications set out in the edictum perpetuum (perpetual edict), as is that of the Digest.

In 529, the failed negotiations of Justin's successor Justinian prompted a Sassanian expedition of 40,000 men towards Dara. The next year, Belisarius was sent back to the region alongside Hermogenes and an army; Kavadh answered with another 10,000 troops under the general Perozes, who set up camp about five kilometers away at Ammodius. In the near vicinity of Dara.

The Battle of Callinicum took place on Easter Saturday, 19 April 531 CE, between the armies of the Byzantine Empire under Belisarius and a Sasanian cavalry force under Azarethes. After a defeat at the Battle of Dara, the Sasanians moved to invade Syria in an attempt to turn the tide of the war. Belisarius' rapid response foiled the plan, and his troops pushed the Persians to the edge of Syria through maneuvering before forcing a battle in which the Sasanians proved to be the pyrrhic victors.

The ancient Roman and Byzantine empires had well-developed associations, known as demes, which supported the different factions (or teams) to which competitors in certain sporting events belonged, especially in chariot racing. There were initially four major factions in chariot racing, differentiated by the colour of the uniform in which they competed; the colours were also worn by their supporters. The demes had become a focus for various social and political issues for which the general Byzantine population lacked other forms of outlet. They combined aspects of street gangs and political parties, taking positions on current issues, including theological problems and claimants to the throne.

In 531 some members of the Blues and Greens were arrested for murder in connection with deaths during rioting after a chariot race. The murderers were to be executed, and most of them were. On January 13, 532, an angry crowd arrived at the Hippodrome for the races. The Hippodrome was next to the palace complex, so Justinian could preside over the races from the safety of his box in the palace. From the start, the crowd hurled insults at Justinian. By the end of the day, at race 22, the partisan chants had changed from "Blue" or "Green" to a unified Nίκα ("Nika", meaning "Win!", "Victory!" or "Conquer!"), and the crowds broke out and began to assault the palace. For the next five days, the palace was under siege. Fires started during the tumult destroyed much of the city, including the city's foremost church, the Hagia Sophia (which Justinian would later rebuild).

The Nika riots are often regarded as the most violent riots in the city's history, with nearly half of Constantinople being burned or destroyed and tens of thousands of people killed.

The Vandal War was a conflict fought in North Africa (largely in modern Tunisia) between the forces of the Byzantine, or East Roman, empire and the Vandalic Kingdom of Carthage, in 533–534 CE. It was the first of Justinian I's wars of reconquest of the lost Western Roman Empire.

The Vandals had occupied Roman North Africa in the early 5th century, and established an independent kingdom there. Under their first king, Geiseric, the formidable Vandal navy carried out pirate attacks across the Mediterranean, sacked Rome and defeated a massive Roman invasion in 468. After Geiseric's death, relations with the surviving Eastern Roman Empire normalized, although tensions flared up occasionally due to the Vandals' militant adherence to Arianism and their persecution of the Nicene native population. In 530, a palace coup in Carthage overthrew the pro-Roman Hilderic and replaced him with his cousin Gelimer. The Eastern Roman emperor Justinian took this as a pretext to interfere in Vandal affairs, and after he secured his eastern frontier with Sassanid Persia in 532, he began preparing an expedition under general Belisarius, whose secretary Procopius wrote the main historical narrative of the war.

The Battle of Tricamarum took place on December 15, 533 between the armies of the Byzantine Empire, under Belisarius, and the Vandal Kingdom, commanded by King Gelimer, and his brother Tzazon. It followed the Byzantine victory at the Battle of Ad Decimum, and eliminated the power of the Vandals for good, completing the "Reconquest" of North Africa under the Byzantine Emperor Justinian I. The main contemporary source for the battle is Procopius, De Bello Vandalico, which occupies Books III and IV of his magisterial Wars of Justinian.

The Gothic War between the East Roman (Byzantine) Empire during the reign of Emperor Justinian I and the Ostrogothic Kingdom of Italy took place from 535 until 554 in the Italian peninsula, Dalmatia, Sardinia, Sicily and Corsica. It was one of the last of the many Gothic Wars with the Roman Empire. The war had its roots in the ambition of the East Roman Emperor Justinian I to recover the provinces of the former Western Roman Empire, which the Romans had lost to invading barbarian tribes in the previous century (the Migration Period). The war followed the East Roman reconquest of the province of Africa from the Vandals.

Historians commonly divide the war into two phases:

• From 535 to 540: ending with the fall of the Ostrogothic capital Ravenna and the apparent reconquest of Italy by the Byzantines.
• From 540/541 to 553: a Gothic revival under Totila, suppressed only after a long struggle by the Byzantine general Narses, who also repelled an invasion in 554 by the Franks and Alamanni.

The Battle of the River Bagradas or Battle of Membresa was an engagement in 536 CE between Byzantine forces under Belisarius and rebel forces under Stotzas. Stotzas had besieged Carthage (capital of the prefecture Africa) shortly before with a force of 8,000 rebels, 1,000 Vandal soldiers (400 had escaped after being captured and sailed back to Africa while the rest were still resisting the Byzantines in Africa), and many slaves. Belisarius had only 2,000 men under his command. Upon Belisarius’ arrival the rebels had lifted the siege. Before battle commenced Stotzas wanted to reposition his troops so the high wind would not aid the Byzantines in the fighting. Stotzas neglected to move any troops to cover this movement. Belisarius, seeing that much of the rebel force was disorganised and exposed, decided to charge the rebels, who almost immediately fled in disorder. Rebel casualties remained relatively light as the Byzantine force was too small to safely chase the fleeing rebels. Instead Belisarius allowed his men to plunder the abandoned rebel camp.

The First Siege of Rome during the Gothic War lasted for a year and nine days, from 2 March 537 to 12 March 538. The city was besieged by the Ostrogothic army under their king Vitiges; the defending East Romans were commanded by Belisarius, one of the most famous and successful Roman generals. The siege was the first major encounter between the forces of the two opponents, and played a decisive role in the subsequent development of the war.

After the disaster at Mediolanum, Narses was recalled and Belisarius confirmed as supreme commander with authority throughout Italy. Belisarius resolved to conclude the war by taking Ravenna but had to deal with the Gothic strongholds of Auximum and Faesulae (Fiesole) first. After both were taken, troops from Dalmatia reinforced Belisarius and he moved against Ravenna. Detachments moved north of the Po and the imperial fleet patrolled the Adriatic, cutting the city off from supplies. Inside the Gothic capital, an embassy came from Constantinople, bearing surprisingly lenient terms from Justinian. Anxious to finish the war and concentrate against the impending Persian war, the Emperor offered a partition of Italy, the lands south of the Po would be retained by the Empire, those north of the river by the Goths. The Goths readily accepted the terms but Belisarius, judging this to be a betrayal of all he had striven to achieve, refused to sign, even though his generals disagreed with him.

Disheartened, the Goths offered to make Belisarius, whom they respected, the western emperor. Belisarius had no intention of accepting the role but saw how he could use this situation to his advantage and feigned acceptance. In May 540 Belisarius and his army entered Ravenna; the city was not looted, while the Goths were well treated and allowed to keep their properties. In the aftermath of Ravenna's surrender, several Gothic garrisons north of the Po surrendered. Others remained in Gothic hands, among which were Ticinum, where Uraias was based and Verona, held by Ildibad. Soon after, Belisarius sailed for Constantinople, where he was refused the honour of a triumph. Vitiges was named a patrician and sent into comfortable retirement, while the captive Goths were sent to reinforce the eastern armies.

The plague of Justinian or Justinianic plague (541–549 CE) was the first major outbreak of the first plague pandemic, the first Old World pandemic of plague, the contagious disease caused by the bacterium Yersinia pestis. The disease afflicted the entire Mediterranean Basin, Europe, and the Near East, severely affecting the Sasanian Empire and the Byzantine Empire and especially its capital, Constantinople.

The plague is named for the Byzantine Emperor Justinian I (r. 527–565) who, according to his court historian Procopius, contracted the disease and recovered in 542, at the height of the epidemic which killed about a fifth of the population in the imperial capital. The contagion arrived in Roman Egypt in 541, spread around the Mediterranean Sea until 544, and persisted in Northern Europe and the Arabian Peninsula, until 549.

Belisarius' departure left most of Italy in Roman hands, but north of the Po, Ticinum and Verona remained unconquered. In the early autumn of 541 Totila proclaimed king.

There were many reasons for early Gothic success:

• the outbreak of the Plague of Justinian devastated and depopulated the Roman Empire in 542
• the beginning of a new Roman–Persian War forced Justinian to deploy most of his troops in the east
• and the incompetence and disunity of the various Roman generals in Italy undermined military function and discipline. This last brought about Totila's first success.

After much urging by Justinian, the generals Constantinian and Alexander combined their forces and advanced upon Verona. Through treachery they managed to capture a gate in the city walls; instead of pressing the attack they delayed to quarrel over the prospective booty, allowing the Goths to recapture the gate and force the Byzantines to withdraw. Totila attacked their camp near Faventia (Faenza) with 5,000 men and, at the Battle of Faventia, destroyed the Roman army.

Following his success against the Byzantines in the Battle of Faventia in spring 542, Totila sent part of his troops to attack Florence. Justin, the Byzantine commander of Florence, had neglected to adequately provision the city against a siege, and hurriedly sent for aid to the other Byzantine commanders in the area: John, Bessas and Cyprian. They gathered their forces and came to the relief of Florence. At their approach, the Goths raised the siege and retreated north, to the region of Mucellium (modern Mugello). The Byzantines pursued them, with John and his troops leading the chase and the rest of the army following behind. Suddenly, the Goths rushed upon John's men from the top of a hill. The Byzantines initially held, but soon a rumour spread that their general had fallen, and they broke and fled towards the oncoming main Byzantine force. Their panic however was caught by the latter as well, and the entire Byzantine army dispersed in disorder.

The Siege of Naples was a successful siege of Naples by the Ostrogothic leader Totila in 542–543 CE. After crushing the Byzantine armies at Faventia and Mucellium, Totila marched south towards Naples, held by the general Conon with 1,000 men. A large-scale relief effort by the newly appointed magister militum Demetrius from Sicily was intercepted and almost entirely destroyed by Gothic warships. A second effort, again under Demetrius, likewise failed when strong winds forced the fleet's vessels to beach, where they were attacked and overrun by the Gothic army. Knowing the dire situation of the city's defenders, Totila promised the garrison safe passage if they surrendered. Pressed by famine and demoralized by the failure of the relief efforts, Conon accepted, and in late March or early April 543, Naples surrendered. The defenders were well treated by Totila, and the Byzantine garrison was allowed safe departure, but the city walls were partly razed.

After more than a year Totila finally entered Rome on 17 December 546, when his men scaled the walls at night and opened the Asinarian Gate. Procopius states that Totila was aided by some Isaurian troops from the imperial garrison who had arranged a secret pact with the Goths. Rome was plundered and Totila, who had expressed an intention to completely level the city, satisfied himself with tearing down about one third of the walls. He then left in pursuit of the Byzantine forces in Apulia.

Belisarius successfully reoccupied Rome four months later in the spring of 547 and hastily rebuilt the demolished sections of wall by piling up the loose stones "one on top of the other, regardless of order". Totila returned, but was unable to overcome the defenders. Belisarius did not follow up his advantage. Several cities, including Perugia, were taken by the Goths, while Belisarius remained inactive and was then recalled from Italy.

In 549, Totila advanced again against Rome. He attempted to storm the improvised walls and overpower the small garrison of 3,000 men, but was beaten back. He then prepared to blockade the city and starve out the defenders, although the Byzantine commander Diogenes had previously prepared large food stores and had sown wheat fields within the city walls. However, Totila was able to suborn part of the garrison, who opened the Porta Ostiensis gate for him. Totila's men swept through the city, killing all but the women, who were spared on the orders of Totila, and looting what riches remained. Expecting the nobles and the remainder of the garrison to flee as soon as the walls were taken, Totila set traps along the roads to neighboring towns that were not yet under his control and many were killed while fleeing Rome. Many of the male inhabitants were killed in the city or while attempting to flee. The city was afterwards repopulated and rebuilt.

In the mid-6th century CE, two Persian monks (or those disguised as monks), with the support of the Byzantine emperor Justinian I, acquired and smuggled silkworm eggs into the Byzantine Empire, which led to the establishment of an indigenous Byzantine silk industry. This acquisition of silk worms from China allowed the Byzantines to have a silk monopoly in Europe.

During 550-51 a large expeditionary force totaling 20,000 or possibly 25,000 men was gradually assembled at Salona on the Adriatic, comprising regular Byzantine units and a large contingent of foreign allies, notably Lombards, Heruls, and Bulgars. The imperial chamberlain (cubicularius) Narses was appointed to command in mid 551. The following spring Narses led this Byzantine army around the coast of the Adriatic as far as Ancona, and then turned inland aiming to march down the Via Flaminia to Rome.

At the Battle of Taginae the forces of the Byzantine Empire under Narses broke the power of the Ostrogoths in Italy, and paved the way for the temporary Byzantine reconquest of the Italian Peninsula.

The Battle of Mons Lactarius took place in 552 or 553 during the Gothic War waged on behalf of Justinian I against the Ostrogoths in Italy. After the Battle of Taginae, in which the Ostrogoth king Totila was killed, the Byzantine general Narses captured Rome and besieged Cumae. Teia, the new Ostrogothic king, gathered the remnants of the Ostrogothic army and marched to relieve the siege, but in October 552 (or early 553) Narses ambushed him at Mons Lactarius (modern Monti Lattari) in Campania, near Mount Vesuvius and Nuceria Alfaterna. The battle lasted two days, and Teia was killed in the fighting. Ostrogothic power in Italy was eliminated, and many of the remaining Ostrogoths went north and (re)settled in south Austria. After the battle, Italy was again invaded, this time by the Franks, but they too were defeated and the peninsula was, for a time, reintegrated into the Empire.

During the later stages of the Gothic War, the Gothic king Teia called upon the Franks for help against the Roman armies under the eunuch Narses. Although King Theudebald refused to send aid, he allowed two of his subjects, the Alemanni chieftains Leutharis and Butilinus, to cross into Italy. According to the historian Agathias, the two brothers gathered a host of 75,000 Franks and Alemanni, and in early 553 crossed the Alps and took the town of Parma. They defeated a force under the Heruli commander Fulcaris, and soon many Goths from northern Italy joined their forces. In the meantime, Narses dispersed his troops to garrisons throughout central Italy, and himself wintered at Rome.

In the spring of 554, the two brothers invaded central Italy, plundering as they descended southwards, until they came to Samnium. There they divided their forces, with Butilinus and the larger part of the army marching south towards Campania and the Strait of Messina, while Leutharis led the remainder towards Apulia and Otranto. Leutharis, however, soon turned back home, laden with spoils. His vanguard, however, was heavily defeated by the Armenian Byzantine Artabanes at Fanum, leaving most of the booty behind. The remainder managed to reach northern Italy and cross the Alps into Frankish territory, but not before losing more men to a plague, including Leutharis himself.

Butilinus, on the other hand, more ambitious and possibly persuaded by the Goths to restore their kingdom with himself as king, resolved to remain. His army was infected by dysentery, so that it was reduced from its original size of 30,000 to a size close to that of Narses' forces. In summer, Butilinus marched back to Campania and erected camp on the banks of the Volturnus, covering its exposed sides with an earthen rampart, reinforced by his numerous supply wagons. A bridge over the river was fortified by a wooden tower, heavily garrisoned by the Franks. The Byzantines, led by the old eunuch general Narses, were victorious against the combined army of Franks and Alemanni.

The emperor Justinian I faced a major Samaritan revolt in 556. On this occasion the Jews and the Samaritans seem to have made common cause, beginning their rebellion in Caesarea early in July. They fell upon the Christians in the city, killing many of them, after which they attacked and plundered the churches. The governor, Stephanus, and his military escort were pressed hard, and eventually the governor was killed, while taking refuge in his own house. Amantius, the governor of the East was ordered to quell the revolt, after the widow of Stephanus reached Constantinople.

Despite the Jewish participation, the rebellion seems to have gathered less support than the revolt of Ben Sabar. The Church of the Nativity was burned down, suggesting that the rebellion had spread south to Bethlehem. Either 100,000 or 120,000 are said to have been butchered following the revolt. Others were tortured or driven into exile. However, this is probably an exaggeration as punishment seems to have been limited to the district of Caesarea.

Although an invasion attempt by the Franks, then allies of the Ostrogoths, late in the war was successfully repelled, a large migration by the Lombards, a Germanic people that had been previously allied with the Byzantine Empire, ensued. In the spring of 568 the Lombards, led by King Alboin, moved from Pannonia and quickly overwhelmed the small Byzantine army left by Narses to guard Italy.

The Lombard arrival broke the political unity of the Italian Peninsula for the first time since the Roman conquest (between the 3rd and 2nd century BCE). The peninsula was now torn between territories ruled by the Lombards and the Byzantines, with boundaries that changed over time.

The newly arrived Lombards were divided into two main areas in Italy: the Langobardia Maior, which comprised northern Italy gravitating around the capital of the Lombard kingdom, Ticinum (the modern-day city of Pavia in the Italian region of Lombardy); and Langobardia Minor, which included the Lombard duchies of Spoleto and Benevento in southern Italy. The territories which remained under Byzantine control were called "Romania" (today's Italian region of Romagna) in northeastern Italy and had its stronghold in the Exarchate of Ravenna.

Justin II inherited a greatly enlarged but overextended empire, with far less resources at his disposal compared to Justinian I. Despite this, he strived to match his formidable uncle's reputation by abandoning the payment of tributes to the Empire's neighbors. This miscalculated move resulted in rekindling of war with the Sassanid Empire, and in a Lombard invasion which cost the Romans much of their territory in Italy.

Justin ceased making payments to the Avars, which had been implemented by his predecessor, Justinian. The Avars almost immediately launched an attack on Sirmium in 568, but were repulsed. The Avars withdrew their troops back to their own territory, but allegedly sent 10,000 Kotrigur Huns, a people who like the Avars had been forced into the Carpathians by the Turkic Khaganate, to invade the Byzantine province of Dalmatia. They then began a period of consolidation, during which the Byzantines paid them 80,000 gold solidi a year.

Except for a raid on Sirmium in 574, they did not threaten Byzantine territory until 579, after Tiberius II stopped the payments. The Avars retaliated with another siege of Sirmium. The city fell in c. 581, or possibly 582. After the capture of Sirmium, the Avars demanded 100,000 solidi a year. Refused, they began pillaging the northern and eastern Balkans, which only ended after the Avars were pushed back by the Byzantines from 597 to 602.

The Byzantine–Sasanian War of 572–591 was a war fought between the Sasanian Empire of Persia and the Eastern Roman Empire, termed by modern historians as the Byzantine Empire. It was triggered by pro-Byzantine revolts in areas of the Caucasus under Persian hegemony, although other events also contributed to its outbreak. The fighting was largely confined to the southern Caucasus and Mesopotamia, although it also extended into eastern Anatolia, Syria, and northern Iran. It was part of an intense sequence of wars between these two empires which occupied the majority of the 6th and early 7th centuries. It was also the last of the many wars between them to follow a pattern in which fighting was largely confined to frontier provinces and neither side achieved any lasting occupation of enemy territory beyond this border zone. It preceded a much more wide-ranging and dramatic final conflict in the early 7th century.

In 575, Tiberius sent reinforcements to Italy under the command of Baduarius with orders to stem the Lombard invasion. He saved Rome from the Lombards and allied the Empire with Childebert II, the King of the Franks, to defeat them. Childebert II fought on several occasions in the name of the Emperor Maurice against the Lombards in Italy, with limited success. Unfortunately, Baduarius was defeated and killed in 576, allowing even more imperial territory in Italy to slip away.

The Strategikon or Strategicon is a manual of war regarded as written in late antiquity (6th century) and generally attributed to the Byzantine Emperor Maurice.

Tiberius rose to power in 574 when Justin II, prior to a mental breakdown, proclaimed Tiberius Caesar and adopted him as his own son. In 578, Justin II, before he died, gave him the title of Augustus, under which title he reigned until his death on 14 August 582.

The Avars decided to take advantage of the lack of troops in the Balkans by besieging Sirmium which falls in 579 CE. At the same time, the Slavs began to migrate into Thrace, Macedonia and Greece, which Tiberius was unable to halt as the Persians refused to agree to a peace in the east, which remained the emperor's main priority. By 582, with no apparent end to the Persian war in sight, Tiberius was forced to come to terms with the Avars, and he agreed to pay an indemnity and to hand over the vital city of Sirmium, which the Avars then looted. The migration of the Slavs continued, with their incursions reaching as far south as Athens.

The Slavic migrations to the Balkans have taken place since the mid-6th century and first decades of the 7th century in Early Middle Ages. The rapid demographic spread of the Slavs was followed by a population exchange, mixing and language shift to and from Slavic. There was no single reason for the Slavic migration that would apply to most of this area to became Slavic-speaking. The settlement was facilitated by the substantial fall of the Balkan population during the Plague of Justinian. Another reason was the Late Antique Little Ice Age from 536 to around 660 CE and the series of wars between the Sasanian Empire and the Avar Khaganate against the Eastern Roman Empire. The backbone of the Avar Khaganate consisted of Slavic tribes.

Maurice's Balkan campaigns were a series of military expeditions conducted by Roman Emperor Maurice (reigned 582–602) in an attempt to defend the Balkan provinces of the Roman Empire from the Avars and the South Slavs. Maurice was the only East Roman emperor, other than Anastasius I, who did his best to implement determined Balkan policies during Late Antiquity by paying adequate attention to the safety of the northern frontier against barbarian incursions. During the second half of his reign, the Balkan campaigns were the main focus of Maurice's foreign policies, as a favourable peace treaty with Persian Empire in 591 enabled him to shift his experienced troops from the Persian front to the region. The refocusing of Roman efforts soon paid off: the frequent Roman failures before 591 were succeeded by a string of successes afterwards.

Although it is widely believed that his campaigns were only a token measure and that Roman rule over the Balkans collapsed immediately after his overthrow in 602, Maurice was actually well on his way to forestalling the Slavic landfall on the Balkans and nearly preserved the order of Late Antiquity there. His success was undone only over ten years after his overthrow.

Retrospectively, the campaigns were the last in the series of classical Roman campaigns against the Barbarians on the Rhine and Danube, effectively delaying Slavic landfall on the Balkans by two decades. With respect to the Slavs, the campaigns had the typical trait of Roman campaigns against unorganized tribes and of what is now called asymmetric warfare.

In June of 582 Maurice scored a decisive victory against Adarmahan near Constantina. Adarmahan barely escaped the field, while his co-commander Tamkhosrau was killed. In the same month Emperor Tiberius was struck down by an illness which shortly thereafter killed him.;

Maurice's reign was troubled by almost constant warfare. After he became Emperor, he brought the war with Sasanian Persia to a victorious conclusion. The Empire's eastern border in the South Caucasus was vastly expanded and, for the first time in nearly two centuries, the Romans were no longer obliged to pay the Persians thousands of pounds of gold annually for peace. Afterwards Maurice campaigned extensively in the Balkans against the Avars – pushing them back across the Danube by 599. He also conducted campaigns across the Danube, the first Roman Emperor to do so in over two centuries. In the west, he established two large semi-autonomous provinces called exarchates, ruled by exarchs, or viceroys of the emperor. In Italy Maurice established the Exarchate of Italy in 584, the first real effort by the Empire to halt the advance of the Lombards. With the creation of the Exarchate of Africa in 591 he further solidified the power of Constantinople in the western Mediterranean.

Maurice's successes on battlefields and in foreign policy were counterbalanced by mounting financial difficulties of the Empire. Maurice responded in several unpopular measures which alienated both the army and the general populace. In 602 a dissatisfied officer named Phocas usurped the throne, having Maurice and his six sons executed. This event would prove a disaster for the Empire, sparking a twenty-six-year war with Sassanid Persia which would leave both empires devastated prior to the Muslim conquests.

The exarchate was organised into a group of duchies (Rome, Venetia, Calabria, Naples, Perugia, Pentapolis, Lucania, etc.) that were mainly the coastal cities in the Italian peninsula since the Lombards held the advantage in the hinterland.

The civil and military head of these imperial possessions, the exarch himself, was the representative at Ravenna of the emperor in Constantinople. The surrounding territory reached from the River Po, which served as the boundary with Venice in the north, to the Pentapolis at Rimini in the south, the border of the "five cities" in the Marches along the Adriatic coast, and reached even cities not on the coast, such as Forlì.;

The Battle of Solachon was fought in 586 CE in northern Mesopotamia between the East Roman (Byzantine) forces, led by Philippicus, and the Sassanid Persians under Kardarigan. The engagement was part of the long and inconclusive Byzantine–Sassanid War of 572–591. The Battle of Solachon ended in a major Byzantine victory which improved the Byzantine position in Mesopotamia, but it was not in the end decisive. The war dragged on until 591, when it ended with a negotiated settlement between Maurice and the Persian shah Khosrau II (r. 590–628).

The Battle of Martyropolis was fought in summer 588 near Martyropolis between an East Roman (Byzantine) and a Sassanid Persian army, and resulted in a Byzantine victory. The Byzantine army of the East had been weakened by a mutiny in April 588, caused by unpopular cost-cutting measures and directed against the new commander, Priscus. Priscus was attacked and fled the army camp, and the mutineers chose the dux of Phoenice Libanensis, Germanus, as their temporary leader.

Emperor Maurice then restored the former commander, Philippicus, to the post, but before he could arrive and take control, the Persians, taking advantage of the disorder, invaded Byzantine territory and attacked Constantina. Germanus organized a force of a thousand men which relieved the siege. As the historian Theophylact Simocatta records, "with difficulty [Germanus] spurred on and incited the Roman contingents with speeches" and managed to assemble 4,000 men and launch a raid into Persian territory.

Germanus then led his army north to Martyropolis, from where he launched another raid across the border into Arzanene. The attack was blocked by the Persian general Maruzas (and possibly corresponds also with the raid defeated in battle at Tsalkajur near Lake Van by the Persian marzban of Armenia, Aphrahat), and turned back.

The Persians under Maruzas followed close behind, and a battle was fought near Martyropolis which resulted in a major Byzantine victory: according to Simocatta's account, Maruzas was killed, several of the Persian leaders were captured along with 3,000 other prisoners, and only a thousand men survived to reach refuge at Nisibis.

The Sasanian civil war of 589–591 was a conflict that broke out in 589, due to the great deal of dissatisfaction among the nobles towards the rule of Hormizd IV. The civil war lasted until 591, ending with the overthrow of the Mihranid usurper Bahram Chobin and the restoration of the Sasanian family as the rulers of Iran.

The reason for the civil war was due to king Hormizd IV's hard treatment towards the nobility and clergy, whom he distrusted. This eventually made Bahram Chobin start a major rebellion, while the two Ispahbudhan brothers Vistahm and Vinduyih made a palace coup against him, resulting in the blinding and eventually death of Hormizd IV. His son, Khosrow II, was thereafter crowned as king.

However, this did not change the mind of Bahram Chobin, who wanted to restore Parthian rule in Iran. Khosrow II was eventually forced to flee to Byzantine territory, where he made an alliance with the Byzantine emperor Maurice against Bahram Chobin. In 591, Khosrow II and his Byzantine allies invaded Bahram Chobin's territories in Mesopotamia, where they successfully managed to defeat him, while Khosrow II regained the throne. Bahram Chobin thereafter fled to the territory of the Turks in Transoxiana, but was not long afterwards assassinated or executed at the instigation of Khosrow II.

The Exarchate of Africa was a division of the Byzantine Empire centered around Carthage, Tunisia, that encompassed its possessions on the Western Mediterranean. Ruled by an exarch (viceroy), it was established by the Emperor Maurice in the late 580s and survived until the Muslim conquest of the Maghreb in the late 7th century. It was, along with the Exarchate of Ravenna, one of two exarchates established following the western reconquests under Emperor Justinian I to administer the territories more effectively.

After the peace treaty with the Persians and subsequent Roman refocusing on the Balkans as mentioned above, Maurice deployed veteran troops to the Balkans, allowing the Byzantines to shift from a reactive strategy to a pre-emptive one. The general Priscus was tasked with stopping the Slavs from crossing the Danube in spring 593. He routed several raiding parties, before he crossed the Danube and fought the Slavs in what is now Wallachia until autumn. Maurice ordered him to make camp on the northern bank of the Danube, however Priscus instead retired to Odessos. Priscus' retreat allowed for a new Slav incursion in late 593/594 in Moesia and Macedonia, with the towns of Aquis, Scupi and Zaldapa being destroyed.

In 594 Maurice replaced Priscus with his own brother, Peter. Due to his inexperience, Peter suffered initial failures, but eventually managed to repulse the tide of Slav and Avar incursions. He set up base at Marcianopolis, and patrolled the Danube between Novae and the Black Sea. In late August of 594, he crossed the Danube near Securisca and fought his way to the Helibacia river, preventing the Slavs and Avars from preparing new pillaging campaigns. Priscus, who had been given command of another army, prevented the Avars from besieging Singidunum in 595, in combination with the Byzantine Danube fleet. After this, the Avars shifted their focus to Dalmatia, where they sacked several fortresses, and avoided confronting Priscus directly. Priscus was not particularly concerned about the Avar incursion, as Dalmatia was a remote and poor province; he sent only a small force to check their invasion, keeping the main body of his forces near the Danube. The small force was able to hamper the Avar advance, and even recovered a part of the loot taken by the Avars, better than expected.

The Battle of the Blarathon was fought in 591 near Ganzak between a combined Byzantine–Persian force and a Persian army led by the usurper Bahram Chobin. The combined army was led by John Mystacon, Narses, and the Persian king Khosrau II. The Byzantine–Persian force was victorious, ousting Bahram Chobin from power and reinstating Khosrau as ruler of the Sassanid Empire. Khosrau was swiftly reinstated upon the Persian throne, and as agreed upon returned Dara and Martyropolis. The Battle of the Blarathon altered the course of Roman-Persian relations dramatically, leaving the former in the dominant position. The extent of effective Roman control in the Caucasus reached its zenith historically. The victory was decisive; Maurice finally brought the war to a successful conclusion with the re-accession of Khosrau.

Peace with the Byzantines was then officially made. Maurice, for his aid, received much of Sasanian Armenia and western Georgia, and received the abolition of tribute which had formerly been paid to the Sasanians. This marked the beginning of a peaceful period between the two empires, which lasted until 602, when Khosrow decided to declare war against the Byzantines after the murder of Maurice by the usurper Phocas.

Emboldened by the plunder from the Franks, the Avars resumed their raids across the Danube in autumn of 597, catching the Byzantines by surprise. The Avars even caught Priscus' army while it was still in its camp in Tomis, and laid siege to it. However, they lifted the siege on 30 March 598, at the approach of a Byzantine army led by Comentiolus, which had just crossed Mount Haemus and was marching along the Danube up to Zikidiba, only 30 kilometres (19 mi) from Tomis. For unknown reasons, Priscus did not join Comentiolus when he pursued the Avars. Comentiolus made camp at Iatrus, however he was routed by the Avars, and his troops had to fight their way back over the Haemus. The Avars took advantage of this victory and advanced to Drizipera, near Constantinople. At Drizipera the Avar forces were struck by a plague, leading to the death of a large portion of their army, and seven sons of Bayan, the Avar Khagan.

The Battles of Viminacium were a series of three battles fought against the Avars by the East Roman (Byzantine) Empire. They were decisive Roman successes, which were followed by an invasion of Pannonia.

In summer 599, the East Roman Emperor Maurice sent his generals Priscus and Comentiolus to the Danube front against the Avars. The generals joined their forces at Singidunum and advanced together down the river to Viminacium. The Avar khagan Bayan I meanwhile - learning that the Romans had determined to violate the peace - crossed the Danube at Viminacium and invaded Moesia Prima, while he entrusted a large force to four of his sons, who were directed to guard the river and prevent the Romans from crossing over to the left bank. In spite of the presence of the Avar army, however, the Byzantine army crossed on rafts and pitched a camp on the left side, while the two commanders sojourned in the town of Viminacium, which stood on an island in the river. Here Comentiolus is said to have fallen ill or to have mutilated himself so as to be incapable of further action; Thus Priscus assumed command over both armies.

A battle was fought which cost the East Romans only three hundred men, while the Avars lost four thousands. This engagement was followed by two other great battles in the next ten days, in which the strategy of Priscus and the tactics of the Roman army were brilliantly successful. Priscus subsequently pursued the fleeing khagan and invaded the Avar homeland in Pannonia, where he won another series of battles on the banks of the River Tisza, deciding the war for the Romans and ending, for a time, the Avar and Slavic incursions across the Danube.

In 602 Maurice, with the lack of money as always dictating policy, decreed that the army should stay for winter beyond the Danube. The exhausted troops mutinied against the Emperor. Probably misjudging the situation, Maurice repeatedly ordered his troops to start a new offensive rather than return to winter quarters. His troops gained the impression that Maurice no longer understood the military situation and proclaimed Phocas their leader. They demanded that Maurice abdicate and proclaim as successor either his son Theodosius or General Germanus. Both men were accused of treason.

As riots broke out in Constantinople, the Emperor, taking his family with him, left the city on a warship heading to Nicomedia, while Theodosius headed east to Persia (historians are not sure whether he had been sent there by his father or if he fled there). Phocas entered Constantinople in November and was crowned emperor. His troops captured Maurice and his family and brought them to the harbor of Eutropius at Chalcedon. Maurice was murdered at the harbor of Eutropius on 27 November 602. The deposed emperor was forced to watch his five younger sons executed before he was beheaded himself.