Between 1815 and 1914, a period referred to as Britain's "imperial century",[3][4] around 10,000,000 square miles (26,000,000 km2) of territory and roughly 400 million people were added to the British Empire.[5] Victory over Napoleonic France left the British without any serious international rival, other than perhaps Russia in Central Asia.[6] When Russia tried expanding its influence in the Balkans, the British and French defeated them in the Crimean War (1853–1856), thereby protecting the Ottoman Empire.