Azerbaijan, officially Republic of Azerbaijan, Country, Transcaucasia, western Asia. Area: 33,436 sq mi (86,600 sq km). Population: (2024 est.) 10,210,000. Capital: Baku. Most residents are of Turkic origin, dating from the 11th century. Later migrations during the Seljūq period brought further groups, including some speaking Persian; Russians are a decreasing minority. Languages: Azerbaijanian (official), Russian.