袁崇焕
The unbroken series of Nurhaci's military successes ended in January 1626 when he was defeated by Yuan Chonghuan while laying siege to Ningyuan. He died a few months later and was succeeded by his eighth son, Hong Taiji, who emerged as the new Khan after a short political struggle amongst other contenders . Although Hong Taiji was an experienced leader and the commander of two Banners at the time of his succession, his reign did not start well on the military front. The Jurchens suffered yet another defeat in 1627 at the hands of Yuan Chonghuan. This defeat was also in part due to the Ming's newly acquired Portuguese cannons.