Ankara, historically known as Ancyra and Angora, is the capital of Turkey. With a population of 4,587,558 in the urban centre (2014) and 5,150,072 in its province (2015), it is Turkey's second largest city after Istanbul (the former imperial capital), having outranked İzmir in the 20th century. Ankara covers an area of 24,521 km2 (9,468 sq mi).