draft a new treaty to replace the Treaty of Sèvres. Invitations to participate in the conference were extended to both the Ankara-based government and the Istanbul-based Ottoman government, but the abolition of the Sultanate by the Ankara-based government on 1 November 1922 and the subsequent departure of Sultan Mehmet VI from Turkey left the Ankara-based government as the sole governing entity in Anatolia. The Ankara-based government, led by Mustafa Kemal Atatürk, moved swiftly to implement its nationalist programme, which did not allow for the presence of significant non-Turkish minorities in Western Anatolia. In one of his first diplomatic acts as the sole governing representative of Turkey, Atatürk negotiated and signed the "Convention Concerning the Exchange of Greek and Turkish Populations" on 30 January 1923 with Eleftherios Venizelos and the government of Greece. The convention had a retrospective effect for all the population moves which took place since the declaration of the First Balkan War, i.e. 18 October 1912 (article 3). However, by the time the agreement was to take effect, 1 May 1923, most of the pre-war Greek population of Aegean Turkey had already fled. The exchange involved the remaining Greeks of central Anatolia (both Greek- and Turkish-speaking), Pontus and Kars. Thus of the 1,200,000 only about 189,916 still remained in Turkey that time. In Greece, it was considered part of the events called the Asia Minor Catastrophe (). Significant refugee displacement and population movements had already occurred following the Balkan Wars, World War I, and the Turkish War of Independence. The convention affected the populations as follows: almost all Greek Orthodox Christians (Greek- or Turkish-speaking) of Asia Minor including the Greek Orthodox populations from middle Anatolia (Cappadocian Greeks), the Ionia region (e.g. Smyrna, Aivali), the Pontus region (e.g. Trabzon, Samsun), the former Russian Caucasus province of Kars (Kars Oblast), Prusa (Bursa), the Bithynia region (e.g., Nicomedia (İzmit), Chalcedon (Kadıköy), East Thrace, and other regions were either expelled or formally denaturalized from Turkish territory. On the other hand, the Muslim population in Greece not having been affected by the recent Greek–Turkish conflict was almost intact. Thus c. 354,647 Muslims moved to Turkey after the agreement. Those Muslims were predominantly Turkish, but a large percentage belonged to Greek, Roma, Pomak, Macedonian, Cham Albanian, Megleno-Romanian, and Dönmeh Muslim communities. For both communities, the population exchange had traumatic psychological effects. Professor Ayse Lahur Kirtunc, a Cretan Muslim expelled to Turkey stated in an