Yuan Chonghuan
Under the brilliant commander Yuan Chonghuan (1584–1630), the Ming were able to repeatedly fight off the Manchus, notably in 1626 at the Battle of Ningyuan and in 1628. Under Yuan's command the Ming had securely fortified the Shanhai Pass, thus blocking the Manchus from crossing the pass to attack the Liaodong Peninsula. Using European firearms acquired from his cook, he was able to stave off Nurhaci's advances along the Liao River. Although he was named field marshal of all the northeastern forces in 1628, he was executed in 1630 on trumped-up charges of colluding with the Manchus as they staged their raids. Succeeding generals proved unable to eliminate the Manchu threat.