 In 1640 , masses of Chinese peasants who were starving , unable to pay their taxes , and no longer in fear of the frequently defeated Chinese army , began to form into huge bands of rebels . The Chinese military , caught between fruitless efforts to defeat the Manchu raiders from the north and huge peasant revolts in the provinces , essentially fell apart . Unpaid and unfed , the army was defeated by Li Zicheng — now self @-@ styled as the Prince of Shun — and deserted the capital without much of a fight . On 26 May 1644 , Beijing fell to a rebel army led by Li Zicheng when the city gates were treacherously opened from within . During the turmoil , the last Ming emperor hanged himself on a tree in the imperial garden outside the Forbidden City . 
