The Russian Empire was an empire that extended across northern Eurasia from 1721 until the proclamation of the Russian Republic in 1917, forming the final era of Tsarist Russia and the wider Russian monarchy. At its height in the late 19th century, it covered about 22,800,000 km2 (8,800,000 sq mi), roughly one-sixth of the world's landmass, making it the third-largest empire in history, behind only the British and Mongol empires. The 1897 Russian census found a population of 126 million with considerable ethnic, linguistic, religious, and socioeconomic diversity.
Source:Wikipedia — Russian Empire →