2. Russian Empire
The Russian Empire reigned from 1721 until 1927 when the February Revolution overthrew it. The Empire stretched over three continents and was only surpassed by the British and Mongol Empires in regards to territory. As the fall of the Ottoman Empire approached the Russian Empire gained momentum and played a huge role in the defeat of Napoleon. In 1897 it was estimated that the populous of the Russian Empire was 125.6 million, making it the third most populated place at the time.