Zhu Yousong 朱由崧 (died 1645), known as the Hongguang Emperor 弘光帝 (r. 1644-1645), was the first emperor of the Southern Ming 南明 (1644-1661). He was a grandson of Emperor Shenzong 明神宗 (the Wanli Emperor 萬曆, r. 1572-1619), and a son of Zhu Changxun 朱常洵, the Prince of Fu 福王, whose title he inherited in 1643. When the court of the Ming dynasty 明 (1368-1644) disintegrated in 1644 by the invasion of the rebel army under Li Zicheng 李自成, and the Manchus invaded northern China, he and Zhu Changfang 朱常淓, Prince of Lu 潞王, fled to the south and came in April 1644 to Huai'an 淮安, Jiangsu, where the supreme commander (zongdu 總督) of Fengyang 鳳陽, Ma Shiying 馬士英, urged him to head an exile government in Nanjing 南京, the former southern capital of the Ming. His Minister of War (bingbu shangshu 兵部尚書) was Shi Kefa 史可法, Minister of Revenue (hubu shangshu 戶部尚書) Gao Hongtu 高弘圖. A few months later he adopted the title of emperor and chose the reign motto Hongguang "Broad Brilliance".
Chinese historians say that he was completely incompetent and spent the day in banquets, while Ma Shiying was handling government affairs. The latter had appointed members of the so-called "eunuch faction" (yandang 閹黨), like Ruan Dayue 阮大鉞, whose members bitterly fought against courtiers of the Donglin Faction (Donglin dang 東林黨) that was headed by Shi Kefa. The turmoils at the court that had so negatively influenced politics in the last decades of the Ming, now continued to haunt the Southern Ming. Shi Kefa and Gao Hongtu were dismissed. Ma Shiying's suggestion to stabilize the situation was to offer the Manchus territory in northern China and so to repeat the situation during the Song dynasty 宋 (960-1279), when the north was also occupied by "barbarians". Ma indeed sent a legation to the north, into the camp of the defector Wu Sangui 吳三桂 who had invited the Manchus to Beijing to get rid of Li Zicheng. He was offered huge amounts of silver, silks and rice, but refused to deceit his new masters. The Manchus crossed the Yangtze in May 1645, and the Hongwu Emperor and his court fled to Wuhu 蕪湖, into the camp of general Huang Degong 黃得功, but another general, Liu Liangzuo 劉良佐, defected to the Manchus and caputred the emperor. The Manchu Dodo 多鐸, Prince Yu 豫親王, besieged Nanjing, but soon the remaining court officials, led by Minister of Rites (libu shangshu 禮部尚書) Qian Qianyi 錢謙益, offered their submission, and surrendered the city. Zhu Yousong was brought to Beijing where he was executed a year later. His temple name is Emperor Anzong 明安宗.