Ottoman Greeks (Greek: Οθωμανοί Έλληνες, ) were ethnic Greeks who lived in the Ottoman Empire (1453–1921), the Republic of Turkey's predecessor. Ottoman Greeks, who were Greek Orthodox Christians, belonged to the Rum Millet (Millet-i Rum). They were concentrated in what is today modern Greece and Greek Macedonia, western Asia Minor (especially in and around Smyrni), central Anatolia (especially Cappadocia), northeastern Anatolia (especially in Erzurum vilayet, in and around Trebizond and in the Pontic Mountains (roughly corresponding to the medieval Greek kingdom of Pontus, which was situated along the southeastern shores of the Black Sea and the highlands of the interior). There were also sizeable Greek communities elsewhere in the Ottoman Balkans, Ottoman Armenia, and the Ottoman Caucasus, including in what, between 1878 and 1917, made up the Russian Caucasus province of Kars Oblast, in which Pontic Greeks, northeastern Anatolian Greeks, and Caucasus Greeks who had collaborated with the Russian Imperial Army in the Russo-Turkish War of 1828-1829 were settled in over 70 villages, as part of official Russian policy to re-populate with Orthodox Christians an area that was traditionally made up of Ottoman Muslims and Armenians.