Question

Which civilization covered the largest area ?

Answer 1

Quick and easy: The Mongol Empire was the largest empire in the world. :)

Answer 2

The Mongol Empire was the largest contiguous empire the world has ever seen. The Mongol Empire covered 9.15 million square miles of land - more than 16% of the earth's landmass. The empire had 110 million people between 1270 and 1309 — more than 25% of the world's population