After the defeat of France in the Revolutionary and Napoleonic Wars (1792–1815), the British Empire emerged as the principal naval and imperial power of the 19th century.[1] Unchallenged at sea, British dominance was later described as Pax Britannica ("British Peace"), a period of relative peace in Europe and the world (1815–1914) during which the British Empire became the global hegemon and adopted the role of global policeman.[2][3][4][5] In the early 19th century, the Industrial Revolution began to transform Britain; by the time of the Great Exhibition in 1851 the country was described as the "workshop of the world".[6] There was relatively free trade within the Empire, though the Imperial Preference was not as comprehensive as some preference systems such as the German Zollverein.
The British Empire became the world's largest economy in 1870 and was responsible for approximately a quarter of global trade at that time.[7] Its economy was surpassed by the United States in 1916.[8]