史可法
A few weeks after the Chongzhen Emperor committed suicide in Beijing in April 1644, some descendants of the Ming imperial house started arriving in Nanjing, which had been the auxiliary capital of the Ming dynasty. Agreeing that the Ming needed an imperial figure to rally support in the south, the Nanjing Minister of War Shi Kefa and the Fengyang Governor-general Ma Shiying (馬士英) agreed to form a loyalist Ming government around the Prince of Fu, Zhu Yousong, a first cousin of the Chongzhen Emperor who had been next in line for succession after the dead emperor's sons, whose fates were still unknown. The Prince was crowned as emperor on 19 June 1644 under the protection of Ma Shiying and his large war fleet. He would reign under the era name "Hongguang" (弘光). The Hongguang regime was ridden with factional bickering that facilitated the Qing conquest of Jiangnan, which was launched from Xi'an in April 1645. He set out from Xi'an on that very day. For examples of the factional struggles that weakened the Hongguang court, see . Greatly aided by the surrender of Southern Ming commanders Li Chengdong (李成東) and Liu Liangzuo (劉良佐), the Qing army took the key city of Xuzhou north of the Huai River in early May 1645, leaving Shi Kefa in Yangzhou as the main defender of the Southern Ming's northern frontiers. The betrayal of these commanders handed over the entire northwestern zone of the Southern Ming, helping the Qing forces to link up. Ma Shiying had under his command in Nanjing indigenous ethnic minority warriors who came all the way from Sichuan.