The victory Aug. 30, 1922, over the Greek military was the last big engagement between the two armies.
The war began with the Greek invasion of İzmir in May 1919 after the end of the First World War with tacit support from the allies, especially Great Britain. The defeated Ottoman Empire was too weak to resist the Greek forces, with initial resistance provided by irregular Turkish units called Kuvay-i Milliye.
The invasion generated a huge reaction in Anatolia and resulted in an independence movement led by officers of the disbanded Ottoman military. Mustafa Kemal Atatürk, who came to lead the officers, succeeded in stemming the Greek invasion and in August 1922 launched a strong counterattack.
Victory in the Dumlupınar Battle on Aug. 30 in the central Anatolian province of Kütahya destroyed the Greek army and Turkish forces entered İzmir on the Aegean coast Sept. 9. The battle brought an end to the war between Greece and Turkey, with Turkey declaring independence on Oct. 29, 1923, after the signing of the Lausanne Treaty.
The date of Aug. 30 has since been celebrated as "Victory Day," with military marches and other official celebrations marking the Turkish victory.