Mongol invasions in the 13th century Mongol invasions devastated the region

Mongol invasions in the 13th century Mongol invasions devastated the region, but also united the Russian principalities under the leadership of Moscow, which gradually freed itself from Mongol rule. The sixteenth century saw the rise of Ivan, The Terrible, the first to call himself Tsar of all the Russias, consolidating power and expanding territory.