What was the largest empire in Europe in 1812?

The largest empire in Europe in 1812 was the French Empire under Napoleon Bonaparte. At its height, it encompassed vast territories across Europe, including France, parts of Italy, the Netherlands, and much of Central and Eastern Europe. Napoleon's conquests significantly altered the political landscape of Europe during this period, although his empire would soon decline following military defeats, particularly in the ill-fated invasion of Russia in 1812.