Batu Khan launches Mongol invasion of Rus

1237

A grandson of Genghis with Subutai at his elbow crossed the Volga with over a hundred thousand horsemen. The winter-frozen rivers became Mongol highways into Rus. Ryazan fell in December after a week's siege; its people were massacred in the snow. The invasion opened two and a half centuries of Mongol dominion over the Russian principalities, a period known simply as the Tatar Yoke.