Greek refugees is a collective term used to refer to the more than one million Greek Orthodox natives of Asia Minor, Thrace and the Black Sea areas who fled during the Greek genocide (1914-1923) and Greece's later defeat in the Greco-Turkish War (1919–1922), as well as remaining Greek Orthodox inhabitants of Turkey who were required to leave their homes for Greece shortly thereafter as part of the population exchange between Greece and Turkey, which formalized the population transfer and barred the return of the refugees. This Convention Concerning the Exchange of Greek and Turkish Populations was signed in Lausanne, on January 30, 1923 as part of the peace treaty between Greece and Turkey and required all remaining Orthodox Christians in Turkey, regardless of what language they spoke, be relocated to Greece with the exception of those in Istanbul and two nearby islands. Although the term has been used in various times to refer to fleeing populations of Greek descent (primarily after the Ionian Revolt, the Fall of Constantinople or the Greek Civil War), the population strength and the influence of the Asia Minor Greeks in Greece itself, has attached the term to the Anatolian Greek population of the early 20th century. At least 300,000 Greek refugees were from Eastern Thrace, whereas at least 900,000 were from Asia Minor. At least 150,000 were from Istanbul, who left the city in three years before 1928.