Who had the greatest empire?

Answer 1

The Roman Empire which straddled three continents. But the largest modern world empire would be the British Empire which contained lands in Europe Australia Asia Africa I think South America and in the 1700s, North America

Answer 2

roman empire

For sheer size, power, and influence the British empire pales all else into insignificance.

In sheer size and power, no empire could equal the empire of Kublai Khan.

Answer 3

Britain.