Moscow is the capital of present-day Russia.
Moscow is the capital and most populous city of Russia , with 13.2 million residents within the city limits and 17.8 million within the urban area . By its territorial expansion on July 1 , 2012 southwest into the Moscow Oblast , the area of the capital more than doubled , going from 1091 to , and it gained an additional population of 233,000 people . The city has served as the capital of a progression of states , from the medieval Grand Duchy of Moscow and the subsequent Tsardom of Russia to the Russian Empire to the Soviet Union and the contemporary Russian Federation .