The Russian Empire (also Russian Empire or Empire of Russia) was a state that existed from 1721 to 1917 in Eastern Europe, Central Asia and North America. The country was the largest contiguous empire in modern history in the mid-19th century. It was dissolved after the February Revolution in 1917. The state was regarded as autocratically ruled and was inhabited by about 181 million people.
The Soviet Union (SU or USSR, Russian: Союз Советских Социалистических Республик (СССР) was a state in Eastern Europe, Central and Northern Asia existing from 1922 to 1991. The USSR was inhabited by about 290 million people and formed the largest territorial state in the world, with about 22.5 million square km. The Soviet Union was a socialist soviet republic with a one-party system.