Whose empire was the largest in history?

At its peak around 1920, the British Empire covered about 35.5 million square kilometres, around 24 percent of the land area of Earth, and ruled over roughly 450 million people, about a fifth to a quarter of the world population. Its territories stretched from Canada and the Caribbean to Africa, India, Australia and the Pacific, which is why it was called the empire on which the sun never sets. The Mongol Empire, founded by Genghis Khan, was the largest contiguous land empire, reaching about 24 million square kilometres in the late 13th century. Most British colonies gained independence in the decades after World War II.