One of the most famous museums in the world, the Hermitage has a vast collection occupying a grand ensemble of buildings. The most impressive is Rastrelli's Baroque Winter Palace, home to the Russian imperial royal family. However, after the assassination of Alexander II in 1881, the tsars rarely lived here. During World War I a field hospital occupied some of the state rooms, and in July 1917, the Provisional Government took the palace as its headquaters, which led to its storming by the Bolsheviks,which in turn led to the revolution, communisum and the Soviet Union.