Russian Empire
The Russian Empire, also known as Imperial Russia or simply Russia, was an empire that existed across Eurasia and North America from 1721, following the end of the Great Northern War, until the Republic was proclaimed by the Provisional Government that took power after the February Revolution of 1917.
Soviet Union
Modern revolutionary activity in the Russian Empire began with the Decembrist revolt of 1825. Although serfdom was abolished in 1861, it was done on terms unfavorable to the peasants and served to encourage revolutionaries. A parliament—the State Duma—was established in 1906 after the Russian Revolution of 1905, but Tsar Nicholas II resisted attempts to move from absolute to constitutional monarchy. Social unrest continued and was aggravated during World War I by military defeat and food shortages in major cities.