Yerevan is the capital and largest city of Armenia, as well as one of the world’s oldest continuously inhabited cities. It is the administrative, academic and cultural center of the country. The city expanded rapidly during the 20th century as part of the Soviet Union. Following the dismantling of the USSR, Yerevan became the capital of the Republic of Armenia on September 21, 1991. Almost half of the entire population of Armenia resides in Yerevan, an estimated 1.5 million people.