By the middle of the 11th century, the role of Kiev as a strong state center started to decline. Before his death, Yaroslav the Wise (1019-1054) divided the state among his 5 sons and a nephew, which inevitably led to conflicts. The situation became even more complicated because of the Pechenegs and Polovtsys - nomadic tribes that constantly raided into territories of Rus in X-XII centuries.

In the beginning of a new millennium the Slavs came from the modern territory of northern Ukraine and southern Belarus and quickly outspread along the eastern European plain. These Slavic tribes were the ancestors of the modern Slavic peoples, and the Russians represent the eastern branch of this group.