Winter is usually a time when armies disband and wars go on pause. The logistics of feeding people and maneuvering an army were such that it was generally recognized as impossible to wage war effectively. The medieval Mongols, however, felt differently. As a nomadic people from a cold place, they were used to the challenges of moving around during the winter. Moreover, it was actually easier to move their massive armies of horses during the winter, because rivers froze over, offering an easy way to cross them. By virtue of the Mongol’s pastoral approach to food, there was usually an excess of stored meat because the herds needed to be culled before winter.
– A few thoughts from your friend Saxo