The Soviet Ruble was the official currency of the Soviet Union, introduced in 1922. It was subdivided into 100 kopecks and was used in various forms throughout the country's history. The ruble was a key part of the planned economy, with its value controlled by the state rather than market forces. The currency underwent several redenominations, particularly in 1947 and 1961, to combat inflation and stabilize the economy. The Soviet Ruble ceased to be legal tender after the dissolution of the Soviet Union in 1991, replaced by national currencies in the newly independent states.