Peter the Great , Peter I or Peter Alexeyevich (;  – ) ruled the Tsardom of Russia and later the Russian Empire from 7 May (O.S. 27 April) 1682 until his death, jointly ruling before 1696 with his elder half-brother, Ivan V. Through a number of successful wars he expanded the Tsardom into a much larger empire that became a major European power. He led a cultural revolution that replaced some of the traditionalist and medieval social and political systems with ones that were modern, scientific, westernized, and based on The Enlightenment. Peter's reforms made a lasting impact on Russia and many institutions of Russian government traced their origins to his reign.