Which was larger: the British Empire or the Mongolian Empire?

Answer 1

Depends on your meaning of the word "larger". As an "every part touching" (contiguous) land mass, the Mongol Empire was; as a "spread out all over the world" (extensive) empire, the British Empire was. There was a time when one could say "The sun never sets on the British Empire", as parts of it were in North and South America, Europe, Africa, the Near East, the Middle East, the Far East, the South Seas, etc., etc.

Answer 2

The British Empire was the largest empire in history by landmass. The Mongolian Empire was the second largest, Russian Empire third.

But the Mongolian Empire was the largest *contiguous* *land* empire in history.