Mongol Empire

The Mongol Empire under Genghis Khan stands as the largest contiguous land empire ever, spanning 24 million square kilometers and covering 16% of Earth's total land. Its Pax Mongolica unified Europe and Asia through trade along the Silk Road, yet its conquests resulted in 40 million deaths, eliminating roughly 10% of the world's population at the time. This dual legacy of connectivity and devastation shapes its historical rank.