Mongols, expanding their empire, continually attacked the region from the south and east, eventually overrunning it in the thirteenth century. The fledgling Russia then relocated north-east in and around the city of Moscow. This early Russia, known as the Grand Principality of Muscovy, was indefensible. There were no mountains, no deserts and few rivers. In all directions lay flatland, and across the steppe to the south and east were the Mongols.
