George I of Greece, born on 24 December 1845 in Copenhagen, was originally a Danish prince destined for a naval career. At the age of 17, he was elected king by the Greek National Assembly after the deposition of King Otto. His election was supported by the Great Powers, including the United Kingdom, France, and Russia. He married Grand Duchess Olga Constantinovna of Russia in 1867, establishing a new Greek dynasty. His reign lasted from 30 March 1863 until his assassination on 18 March 1913, making it the longest in modern Greek history.George's reign was marked by significant territorial expansion. Greece gained the Ionian Islands from Britain in 1864 and annexed Thessaly from the Ottoman Empire following the Russo-Turkish War of 1877-1878. However, Greece faced setbacks, notably in the Greco-Turkish War of 1897, where it suffered defeat. George was assassinated in Thessaloniki during the First Balkan War, shortly after Greek forces had captured much of Macedonia.George was the second son of Prince Christian of Schleswig-Holstein-Sonderburg-Glücksburg and Princess Louise of Hesse-Kassel. His family became Danish princes in 1853 when his father was designated heir to the Danish throne. George was educated in Danish, English, French, and German, and initially pursued a naval career. Following Otto's expulsion in 1862, the Greek people sought a monarchy and elected George as king, who took the regnal name George I.Upon his arrival in Greece, George sought to distance himself from Danish influence and quickly learned Greek. He worked to restore the royal palace and engaged with the public more informally than his predecessor. He also initiated constitutional reforms, leading to the establishment of a unicameral assembly in 1864, which allowed for direct, secret, universal male suffrage.George's marriage to Olga Constantinovna produced eight children, and he maintained strong ties with various European royal families. His reign saw political instability, with frequent changes in government. The political landscape was characterized by alternating leadership between Charilaos Trikoupis and Theodoros Deligiannis, who had differing views on Greece's territorial ambitions.In the late 19th century, Greece experienced economic growth and national pride, highlighted by the revival of the Olympic Games in 1896. However, the desire for territorial expansion led to conflict with the Ottoman Empire, culminating in the disastrous Greco-Turkish War of 1897. Despite initial public support, the defeat led to a decline in George's popularity, although he regained favor after surviving an assassination attempt in 1898.In the early 20th century, George's relations with Britain remained strong, particularly after the death of Queen Victoria in 1901. His son, Prince George, served as Governor-General of Crete, but political tensions arose with the Young Turk Revolution in 1908. The military league's demands for reform led to a constitutional revision, and new elections were held in 1910, resulting in Eleftherios Venizelos becoming prime minister.The First Balkan War began in 1912, with Greece joining Serbia, Bulgaria, and Montenegro against the Ottoman Empire. George returned to Greece to oversee military operations, and the Greek forces achieved significant victories, reclaiming Thessaloniki and other territories. However, on 18 March 1913, while walking in Thessaloniki, George was assassinated by Alexandros Schinas, who claimed to have acted for personal reasons. His death marked the end of a significant era in Greek history, and his body was returned to Athens for burial.