Based on peak land area, the British Empire rules as the largest empire in human history. Almost 412 million people lived under the control of the British Empire in 1913, or about 23% of the world population. At its peak in 1920, the British Empire controlled 13.71 million square miles, or almost a quarter of the world’s land area. However, today the British Empire is a shadow of its former self, with only has 17 small dependent and unincorporated territories across the world.
The second largest empire was the Mongol Empire, the largest contiguous land empire during the 13th and 14th centuries, covering an impressive 9.27 million square miles. It originated in Mongolia, but spanned from the Sea of Japan to Eastern Europe, enveloping the Middle East and the Indian subcontinent.
The third largest empire in human history was the Russian Empire, with a peak land area of 8.8 million miles in 1895.