Peter the Great was a Russian czar from 1682 to 1725 who modernized Russia through widespread reforms. He established Russia as a world power by creating a strong navy and westernizing his army and government. Peter obtained new lands, founded the city of St. Petersburg, and defeated Sweden at the Battle of Poltava, expanding Russian territory. Though a harsh ruler, Peter transformed Russia from a medieval state into a major European empire through cultural, social, and political reforms that established Russia as a modern nation.