Constantine I of Greece

Constantine I became King of Greece in 1913 after his father's assassination, having already led Greek forces to triumph in the Balkan Wars of 1912-1913 under Prime Minister Eleftherios Venizelos. Educated in Germany and married to Kaiser Wilhelm II's sister Sophia, he twice dismissed Venizelos and blocked Greece's entry into World War I on the Allied side, sparking the National Schism that divided the country between royalist Old Greece and pro-Venizelos New Greece. His refusal cost Greece Fort Roupel and Macedonian territory to Bulgaria; his paramilitary units attacked Venizelos supporters and fired on Allied troops in Athens. A five-month Allied blockade forced his abdication in 1917, but after his successor Alexander died and Venizelos lost the 1920 elections, Constantine returned to the throne. The disastrous Greco-Turkish War ended in the destruction of Greek communities in Asia Minor; an army revolt drove him to abdicate again in September 1922. He died four months later in exile in Sicily.