Peter I the Great or Pyotr Alexeyevich Romanov (June 1672-8 February 1725) ruled Russia and later the Russian Empire from 7 May 1682 until his death, jointly ruling before 1696 with his weak and sickly half-brother, Ivan V. Peter carried out a policy of Westernization and expansion that transformed the Tsardom of Russia into the 3-billion acre Russian Empire, a major European power.