The House of Romanov (Рома́нов, pronounce [rʌˈmanəf]) was the second and last imperial dynasty of Russia, which ruled the country from 1613 to 1761. From 1761 to 1917, Russia was ruled for five generations by a line of the House of Oldenburg descended from the marriage of a Romanov grand duchess to the Duke of Holstein-Gottorp. This line was officially also called Romanov, although genealogists sometimes style it, more accurately, Holstein-Gottorp-Romanov.