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,
Islam in Greece aimed to give the impression that the Muslims of the region are the descendants of Ottoman-era ethnic Greek converts to Islam like the Vallahades of pre-1923 Greek Macedonia and so thereby avoid a possible future situation in which Western Thrace is ceded to Turkey on the basis of the ethnic origin of its Muslim inhabitants. The term "Muslim minority" (Μουσουλμανική μειονότητα "Musulmanikí mionótita") refers to an Islamic religious, linguistic and ethnic minority in western Thrace, which is part of the Greek administrative region of East Macedonia and Thrace. In 1923, under the terms of the Treaty of Lausanne, the Greek