Mongol Offensive. The Mongol attacks on China between 1483 and 1489 signaled the end of Chinese expansion in the North. Beginning in 1540 the Mongols were making good progress toward unification, posing a serious threat to the Ming dynasty (1368-1644). The Jiajing emperor had to deal with the rise of a new Mongol empire under Altan Khan, who raided Chinese territory in an effort to get supplies for his campaigns against his enemies. In 1550 the Mongolian army beleaguered Beijing for three days and looted the surrounding areas. In 1552 Altan Khan occupied part of Shanxi province. To extend his influence in Central Asia, he invaded Qinghai in 1559 and Tibet in 1570. The Ming court attempted to bribe the Mongols and to strengthen the Great Wall, but these raids continued until Altan Khan reached a temporary peace agreement with the Chinese in 1572. The Mongols, however...