Greco-Turkish War (1919–1922)
The Greek campaign was launched primarily because the western Allies, particularly British Prime Minister David Lloyd George, had promised Greece territorial gains at the expense of the Ottoman Empire, recently defeated in World War I. The armed conflict started when the Greek forces landed in Smyrna (now Izmir), on 15 May 1919. They advanced inland and took control of the western and northwestern part of Anatolia, including the cities of Manisa, Balıkesir, Aydın, Kütahya, Bursa and Eskişehir. Their advance was checked at the Battle of Sakarya in 1921 by forces of the Turkish national movement. The Greek front collapsed with the Turkish counter-attack in August 1922, and the war effectively ended with the recapture of Smyrna by the Turkish forces and the Great Fire of Smyrna.
Diplomatic history of World War I
Repeatedly, both sides violated Greek neutrality. Venizelos allowed the Allies the use of Salonika as a port to attack Bulgaria, but at this point Greece did not join the Allies. The Allied armies failed to advance beyond Salonika. In summer of 1916, the Athens government under King Constantine handed over Fort Roupel to the Germans, calling it a neutral act; it was denounced as a betrayal by the Venizelists. Allied forces fought the war from the Salonika base, engaging Bulgarian forces when they invaded Greece in August 1916 in the Battle of Struma. British and French troops landed in Athens in December 1916, hoping to overthrow the king, but failed and were forced to withdraw. The Allies then blockaded Greek areas supporting the king and finally forced his abdication in June 1917. His son became king and supported Venizelos. At long last Greece declared war on the Central Powers on 30 June 1917. There was little movement on the front until the spring of 1918 and the Greek victory at the Battle of Skra-di-Legen, followed by the Allied offensive in autumn 1918 that broke German, Austro-Hungarian and Bulgarian lines. After the Allies were victorious, Greece expected a large slice of Turkey in the spoils, but was defeated militarily in the Greco-Turkish War (1919–1922). Britain kept Cyprus, and Greece wound up with only Western Thrace. Its most grievous legacy was profound political and social turmoil known as the "National Schism" that polarized Greece into two hostile political camps for generations.