Population exchange between Greece and Turkey

In 1923 Greece and Turkey agreed to a compulsory transfer of their religious minorities, a compulsory exchange on a scale never before attempted in modern times. Defined by religion rather than language, it formally uprooted around 1.2 million Orthodox Christians from Anatolia and Eastern Thrace and some 355,000 to 400,000 Muslims from Greece. Most of the Christians had in fact already fled before the agreement was signed, while most of the Muslims left Greece in 1923 and 1924.

The exchange grew out of the Greco-Turkish War and the violence that preceded it. During and after the First World War, the Christian communities of the Ottoman Empire suffered deportations and massacres, including the Armenian genocide and the killings of Ottoman Greeks, for whom scholars' estimates of the dead range from about 300,000 to 900,000. The Greek occupation of western Anatolia from 1919 brought further atrocities against Muslim civilians. When the Greek army collapsed in 1922, a mass exodus followed: by some calculations around 900,000 Greeks reached Greece in the autumn of that year.

As early as March 1922 the Ankara government's foreign minister, Yusuf Kemal, said Turkey was ready to accept an exchange. On 16 October 1922, after Greece's defeat, the former Greek prime minister Eleftherios Venizelos formally asked the League of Nations for a compulsory exchange. The League's high commissioner for refugees, Fridtjof Nansen, organised it, citing earlier Balkan precedents such as the Greek–Bulgarian exchange of 1919. Both governments had concluded that protecting minorities would not be enough. The Convention Concerning the Exchange of Greek and Turkish Populations was signed at Lausanne on 30 January 1923, ahead of the main peace treaty concluded there that July.

From 1 May 1923, Orthodox Christian citizens of Turkey and Muslim citizens of Greece were to be exchanged. This swept up Turkish-speaking Karamanlides and Greek-speaking Muslims such as the Cretan Muslims alike. The Greeks of Istanbul and the islands of Imbros and Tenedos were exempted, as were the Muslims of Western Thrace, though Greeks who had fled Istanbul during the war were not allowed back. Refugees could take movable belongings, and a commission was to value the property they left behind.

For Greeks, the exchange is bound up with the loss of communities that had lived in Asia Minor, Pontus and Thrace for centuries, part of what Greeks call the Asia Minor Catastrophe. Turkish representatives argued that minorities would be safest without outside interference, and Ankara saw incoming Muslims as settlers for abandoned villages, also pointing to large numbers of Muslims displaced from the Balkans. Historians remain divided: Norman Naimark and Dinah Shelton have described it as completing an ethnic cleansing of Anatolia's Greeks, and others call it legalised mutual expulsion, while some argue that it prevented further massacres.

In Greece, the 1928 census recorded 1,221,849 refugees, about a fifth of the population, and 45 per cent of the people of Greek Macedonia. Many settled on land vacated by departing Muslims; others were placed in shanty towns around Athens and Thessaloniki. The government needed a League of Nations loan, and newcomers often met suspicion from locals. Politically, they largely backed Venizelos, and in later years some turned to the Communist Party. In Turkey, arriving Muslims found many abandoned homes already plundered or occupied, disease killed many during the journey, and the loss of the Greek merchant class left the new state's bureaucracy unchallenged.

The exchange made both countries far more religiously uniform. In 1906 nearly 20 per cent of the population of what is now Turkey was non-Muslim; by 1927 the figure was 2.6 per cent. The exempted Istanbul Greeks, about 200,000 in 1924, dwindled through discriminatory laws, the 1955 pogrom and expulsions in 1964 to just over 2,500 by 2006. Greece, meanwhile, was transformed by the arrival of the refugees and their culture.

Our 1920 map shows the Ottoman Empire before the exchange, and our 1930 map shows Greece and the Republic of Turkey after it.