The British Empire comprised the dominions, colonies, protectorates, mandates and other territories ruled or administered by the United Kingdom and its predecessor states. It originated with the overseas possessions and trading posts established by England between the late 16th and early 18th centuries. At its height, it was the largest empire in history and, for over a century, was the foremost global power. By 1913, the British Empire held sway over 412 million people, 23% of the world population at the time, and by 1920, it covered 35,500,000 km2 (13,700,000 sq mi), 24% of the Earth's total land area. As a result, its political, legal, linguistic and cultural legacy is widespread. At the peak of its power, the phrase "the empire on which the sun never sets" was often used to describe the British Empire, because its expanse around the globe meant that the sun was always shining on at least one of its territories.
During the Age of Discovery in the 15th and 16th centuries, Portugal and Spain pioneered European exploration of the globe, and in the process established large overseas empires. Envious of the great wealth these empires generated, England, France, and the Netherlands began to establish colonies and trade networks of their own in the Americas and Asia. A series of wars in the 17th and 18th centuries with the Netherlands and France left England and then, following union between England and Scotland in 1707, Great Britain, the dominant colonial power in North America. It then became the dominant power in the Indian subcontinent after the East India Company's conquest of Mughal Bengal at the Battle of Plassey in 1757.
The independence of the Thirteen Colonies in North America in 1783 after the American War of Independence caused Britain to lose some of its oldest and most populous colonies. British attention soon turned towards Asia, Africa, and the Pacific. After the defeat of France in the Revolutionary and Napoleonic Wars (1792–1815), Britain emerged as the principal naval and imperial power of the 19th century. 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. In the early 19th century, the Industrial Revolution began to transform Britain; so that by the time of the Great Exhibition in 1851, the country was described as the "workshop of the world". The British Empire expanded to include most of India, large parts of Africa and many other territories throughout the world. Alongside the formal control that Britain exerted over its own colonies, its dominance of much of world trade meant that it effectively controlled the economies of many regions, such as Asia and Latin America.