Albanian-speakers of Western Thrace migrated towards today's European Turkey (Eastern Thrace), especially near Istanbul. Many Muslim Albanians achieved high office in Ottoman society and many of them, most notably the Köprülü family, became Grand Viziers of the Empire. The majority of the Albanian emigration came from Northern Kosovo and the Korça region of Albania. Descendants of this immigrants would later play an important role in the National Renaissance of Albania. The number of Albanians that resided in the region is unknown, as statistical data of the Ottoman Empire were based on religious identification (millets). Thus, the Orthodox Albanians were part of the Rûm millet,
East Thrace the distribution of ethnoreligious groups in the local "sanjaks" was as follows: The Muslim "millet" was recorded as Turkish, while the church members of the Ecumenical Patriarchate as Greek. In the past century modern East Thrace was the main component of the territory of the Adrianople Vilayet, which excluded the Constantinople Vilayet, but included West Thrace and parts of the Rhodopes and Sakar. A publication from December 21, 1912 in the Belgian magazine "Ons Volk Ontwaakt" (‘Our Nation Awakes’) estimated 1,006,500 inhabitants in the vilayet: East Thrace East Thrace or Eastern Thrace ( or simply "Trakya"; , "Anatoliki Thraki"; ,