Ukraine prospered for several centuries in the Middle Ages until its 1240 conquest by these forces from the East
At its greatest extent in the mid-11th century, it stretched from the Baltic 
Sea .... Rurik led the Rus' until his death in about 879, bequeathing his kingdom 
to... [DOC] [TLE] Mongol invasion of Rus' - Wikipedia [PAR] The Mongol Empire invaded Kievan Rus' in the 13th century, destroying 
numerous cities, including Ryazan, Kolomna, Moscow, Vladimir, and Kiev, part of 
the Mongol invasion of Europe.