Moscow is situated on the Moskva River in the Central Federal District of European Russia. In the course of its history 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 Soviet Union. At the beginning of the century many changes were happening in the capital, and architecture answered to these revolutions in many ways. In January 1905, for example, the institution of the City Governor, was officially introduced in Moscow. Following the Russian Revolution of 1917, on 12 March 1918 Moscow became the capital of the Russian Soviet Federative Socialist Republic and of the Soviet Union less than five years later. Current capital of Russia