Meanwhile, Ming government officials fought against each other, against fiscal collapse, and against a series of peasant rebellions. They were unable to capitalise on the Manchu succession dispute and the presence of a minor as emperor. In April 1644, the capital, Beijing, was sacked by a coalition of rebel forces led by Li Zicheng, a former minor Ming official, who established a short-lived Shun dynasty. The last Ming ruler, the Chongzhen Emperor, committed suicide when the city fell to the rebels, marking the official end of the dynasty.