Constantine I of Greece

Constantine I (Greek: Κωνσταντίνος Αʹ, romanized: Konstantínos I; 2 August [O.S. 21 July] 1868 – 11 January 1923) was King of Greece from 18 March 1913 to 11 June 1917 and again from 19 December 1920 to 27 September 1922. The eldest son of George I of Greece, he succeeded to the throne following his father's assassination in 1913.

Educated in Greece and later in Germany, Constantine was an admirer of Prussian militarism. As the crown prince, he was commander-in-chief of the Hellenic Army during the unsuccessful Greco-Turkish War of 1897. Later and under the leadership of Prime Minister Eleftherios Venizelos, he led successfully the Greek forces in the Balkan Wars of 1912–1913, in which Greece expanded, doubling in area and population.

He was married to Sophia of Prussia, a younger sister of Wilhelm II, the Emperor of Germany. During his reign, Constantine's pro-German aligned interests led him to twice refuse Venizelos' popular elected mandates for Greece to join World War I on the side of Allies. Constantine unconstitutionally dismissed his Prime Minister, causing the National Schism. The country was split between the pro-Venizelos New Greece (lands of recently liberated in the Balkan Wars) and the royalist Old Greece, driving deep social cleavages and brought Greece at the brink of civil war. In late 1916, his pro-German policies led to the unconditional surrender of Fort Roupel and the loss of much of newly conquered Macedonian territories to Bulgaria. Also his military staff organized paramilitary units to terrorize Venizelos' supporters, and these groups opened fire against Allied troops in Athens in an incident later known as the Noemvriana. After a five-month naval blockade of Athens by France and Great Britain that caused famine, Constantine abdicated, despite strong popular support for continued resistance. His second son, Alexander, succeeded him. After Alexander's death, Venizelos' defeat in the 1920 legislative elections, and a plebiscite in favor of his return, Constantine was reinstated.

The royalist governments that succeeded Venizelos, continued the unsuccessful Greco-Turkish War of 1919–1922 that ended in the irrevocable destruction of Greek communities in Asia Minor. Constantine I abdicated the throne in favor of his eldest son George II in September 1922, after an army revolt of Venizelist officers. He went to exile, dying in Sicily, Italy on 11 January 1923.