What was the largest empire to have ever existed?

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.

Though Britain and the empire emerged victorious from the Second World War, the effects of the conflict were profound, both at home and abroad. Much of Europe, a continent that had dominated the world for several centuries, was in ruins, and host to the armies of the United States and the Soviet Union, who now held the balance of global power. Britain was left essentially bankrupt.

The UK slowly began the process of decolonisation. Hong Kong was handed back to China in 1997. For many, this was the end of the Empire.