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 be Mediterranean in character. It can descend to about 12°C and can rise to about 32°C, similar to Asian Turkey. East Thrace has an area of 23,764 km (3 percent of the country), slightly smaller than Sardinia, and a population of about 11 million people or about 14 percent of the total population (in 2015); the population density is around 430 people/km, compared to about 80 people/km for Asiatic Turkey, which is also called Anatolia or Asia Minor. However, densities are skewed by the metropolis of Istanbul. The two continents are separated by the Dardanelles, the Bosphorus (collectively known as