When did Turkey become a republic?
Republic Day (Turkey)
The holiday commemorates the events of 29 October 1923, when Mustafa Kemal Atatürk declared that Turkey was henceforth a republic. Turkey had "de facto" been a republic since 23 April 1920, the date of the establishment of the Grand National Assembly of Turkey, but the official confirmation of this fact came only three-and-a-half years later. On 29 October 1923, the status of the nation as a republic was declared and its official name was proclaimed to be ("the Republic of Turkey"). After that, a vote was held in the Grand National Assembly, and Atatürk was elected as the first President of the Republic of Turkey.
History of Ankara
Following the Ottoman defeat during World War I, the Ottoman capital Constantinople was occupied by the Allies. The Turkish nationalist movement, under Kemal Atatürk, established its headquarters in Ankara in 1920 (see Turkish War of Independence). After the War of Independence was won, the Turkish nationalists abolished the Ottoman Empire on October 29, 1923. A few days earlier, on October 13, 1923, Ankara had replaced Constantinople as its capital, and it became the capital city of the new Republic of Turkey.