The Russian Empire was an empire that extended 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. The third-largest empire in history, at its greatest extent stretching over three continents, Europe, Asia, and North America, the Russian Empire was surpassed in size only by the British and Mongol empires. The rise of the Russian Empire coincided with the decline of neighboring rival powers: the Swedish Empire, the Polish–Lithuanian Commonwealth, Persia and the Ottoman Empire. It played a major role in 1812–1814 in defeating Napoleon's ambitions to control Europe and expanded to the west and south.
The House of Romanov ruled the Russian Empire from 1721 until 1762. Its matrilineal branch of patrilineal German descent, the House of Holstein-Gottorp-Romanov, ruled from 1762 to the end of the empire. At the beginning of the 19th century, the Russian Empire extended from the Arctic Ocean in the north to the Black Sea in the south, from the Baltic Sea on the west into Alaska and Northern California in America on the east.