Pax Britannica (Latin for "British Peace", modelled after Pax Romana) was the period of relative peace in Europe (1815–1914) during which the British Empire became the global hegemonic power and adopted the role of a global police force.
Between 1815 and 1914, a period referred to as Britain's "imperial century," around 10,000,000 square miles (26,000,000 km2) of territory and roughly 400 million people were added to the British Empire. Victory over Napoleonic France left the British without any serious international rival, other than perhaps Russia in central Asia. When Russia tried expanding its influence in the Balkans, the British and French defeated it in the Crimean War (1854–56), thereby protecting the by-then feeble Ottoman Empire.
Britain's Royal Navy controlled most of the key maritime trade routes and enjoyed unchallenged sea power. Alongside the formal control it exerted over its own colonies, Britain's dominant position in world trade meant that it effectively controlled access to many regions, such as Asia and Latin America. British merchants, shippers and bankers had such an overwhelming advantage over everyone else that in addition to its colonies it had an "informal empire".
After losing the American colonies in the American Revolution, Britain turned towards Asia, the Pacific and later Africa with subsequent exploration leading to the rise of the Second British Empire (1783–1815). The Industrial Revolution began in Great Britain in the late 1700s and new ideas emerged about free markets, such as Adam Smith's The Wealth of Nations (1776). Free trade became a central principle that Britain practiced by the 1840s. It played a key role in Britain's economic growth and financial dominance.