Zu Dashou
In 1631, Zu Dashou was serving as commander of the Jinzhou garrison. He was leading his troops on an inspection of Dalinghe (present-day Linghai city) when Hong Taiji, commanding a force of 20,000 Manchu, Mongol, and Han Chinese troops, arrived to attack the city on September 1. At Dalinghe, Zu commanded an army of 14,000 men, half infantry and half cavalry, many of whom were veterans of his previous battles with Manchu forces. The presence of Zu's men was made known to Hong Taiji when his patrols captured a Chinese resident outside the city. Instead of attacking the city directly, the Manchu forces prepared for a long siege, building a moat around the city, and guarding the roads with newly formed artillery units armed with Portuguese cannons under the command of the Chinese general Tong Yangxing.