The Russian Empire (Pre-reform Russian orthography: Россійская Имперія, Modern Russian: Российская империя, translit: Rossiyskaya Imperiya) is a country situated in northern Eurasia. It is a semi-constitutional monarchy that existed from 1721 to the present. One of the largest empires in world history, stretching over three continents, the Russian Empire surpassed in landmass only by the British and Mongol empires. It played a major role in 1812–14 in defeating Napoleon's ambitions to control Europe, and expanded to the west and south. It was often in conflict with the Ottoman Empire (which in turn was usually protected by the British).