Dayan Khan
From 1513, Mongol invasions of the Ming Empire recommenced. Dayan Khan built forts in Xuanhua and Datong. He also stationed 15,000 cavalry on Ming territory. His Mongols numbering up to 70,000 invaded the Ming Empire in 1514 and 1517. His sons established a series of permanent bases along the Ming border where the Mongols could keep watch on the Ming troops. Batumongke Dayan Khan repeatedly sought trade relation with the Ming, but rejection turned him more and more to outright warfare.