In the 19th century, the Russian Empire began to expand and spread into Central Asia. There were 210,306 Russians living in Uzbekistan in 1912. The "Great Game" period is generally regarded as running from approximately 1813 to the Anglo-Russian Convention of 1907. A second, less intensive phase followed the Bolshevik Revolution of 1917. At the start of the 19th century, there were some  separating British India and the outlying regions of Tsarist Russia. Much of the land between was unmapped.