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,
Thrace (theme) the Palaiologan period, but it is still encountered in some historians of the time as an antiquarian term. Thrace (theme) The Theme of Thrace () was a province ("thema" or theme) of the Byzantine Empire located in the south-eastern Balkans, comprising varying parts of the eponymous geographic region during its history. Traditionally, it has been held that the theme (at the time primarily a military command) was constituted in c. 680, as a response to the Bulgar threat. This is based on the mention of a certain "patrikios" Theodore, Count of the "Opsikion" and "hypostrategos" of Thrace, in 680/681. However,