The history of Russia dates back to the formation of the East Slavic state known as Kievan Rus' in the 9th century. This early state laid the foundation for Russian culture and governance. Over time, the Mongol invasion in the 13th century led to the fragmentation of the region, but the Grand Duchy of Moscow eventually emerged as a powerful entity, uniting various Russian principalities. In the 18th century, under the rule of Peter the Great, Russia expanded its territory and modernized its military and government. The 19th century saw significant social and political changes, culminating in the Russian Revolution of 1917, which established the Soviet Union. After decades of communist rule, Russia transitioned to a federation in 1991, marking the end of the Soviet era.