The ancestors of Russians are Russian tribes of Eastern Slavs. /kloc-At the end of 0/5, Russian Grand Duke Ivan III of Russia established the Grand Duchy of Moscow. Ivan IV claimed to be the Tsar in 1547, and established Tsarist Russia. In 172 1, Peter the Great renamed it the Russian Empire. The Soviet regime was established after the October Revolution of 19 17. 1922 12, the Union of Soviet Socialist Republics was formally established, and later became a "superpower" that kept pace with the United States during the Cold War. [