Seven Largest Empires Ranked by Peak Territory in Historical Survey

A historical survey ranks the seven largest empires by peak land area, led by the British Empire at 13.71 million square miles in 1920, roughly 24% of the world's land surface. The Mongol Empire follows at 9.27 million square miles, the largest contiguous land empire, with a population of about 110 million, 25% of the world's people. The Russian Empire reached 8.8 million square miles by 1866, sold Alaska to the United States for $7.2 million in 1867, and built Fort Ross in Northern California in 1812. The Qing Dynasty peaked around 1790 at 5.68 million square miles, with over 400 million people by the mid-19th century; the Xinhai Revolution ended it on February 12, 1912, when six-year-old Puyi was removed. The Spanish Empire covered 5.29 million square miles at its late 18th-century height, after Columbus's 1492 voyage and conquests of the Aztecs and Incas. The French colonial empire peaked in the 1920s at 4.44 million square miles, beginning with the 1830 invasion of Algeria. The Umayyad Caliphate reached 4.29 million square miles in the early 8th century and was succeeded by the Abbasid Caliphate in AD 750. The ranking notes that historical claims and land-area metrics vary by source, so positions are not beyond debate.