Was Britain the biggest country for many years ago?

The UK has never been the biggest country, but it had the largest empire that has ever existed by landmass. In 1920, it covered 35.5 million km2 (24% of the Earth's landmass). By comparison, the Mongolian Empire was the largest contiguous empire that has every existed (contiguous means the landmass was all connected by land), with 24 million km2 (16.11% of the Earth's landmass).