Kazan is renowned for its vibrant mix of Tatar and Russian cultures. Following the dissolution of the Soviet Union, Kazan remained the capital of the Republic of Tatarstan. In 1920, after the Russian SFSR became a part of the Soviet Union, Kazan became the capital of the Tatar Autonomous Soviet Socialist Republic (Tatar ASSR). In the following centuries, Kazan grew to become a major industrial, cultural and religious centre of Russia. The city was seized (and largely destroyed) during Pugachev's Rebellion (1773–1775), but was later rebuilt during the reign of Catherine the Great. Historically, Kazan was the capital of the Khanate of Kazan, and was conquered by Ivan the Terrible in the 16th century, at which point the city became a part of the Tsardom of Russia. Kazan is the fifth-largest city in Russia, being the most populous city on the Volga, as well as within the Volga Federal District. The city lies at the confluence of the Volga and the Kazanka Rivers, covering an area of 425.3 square kilometres (164.2 square miles), with a population of over 1.3 million residents, and up to nearly 2 million residents in the greater metropolitan area. Kazan ( / k ə ˈ z æ n, - ˈ z ɑː n/ kə- ZAN, - ZAHN Russian: Казань, IPA: Tatar: Казан, IPA: ) is the largest city and capital of Tatarstan, Russia.