Emperor Modi of Jin

Emperor Mo of Jin, personal name Hudun, sinicised name Wanyan Chenglin, was the last emperor of the Jurchen-led Jin dynasty, which ruled northern China between the 12th and 13th centuries. Originally a military general, he inherited the throne from his predecessor, Emperor Aizong, during the siege of Caizhou. He was killed in action on the same day he was crowned emperor, when Caizhou fell to the allied forces of the Mongol Empire and Southern Song dynasty. Having ruled as emperor for less than a day, or maybe even just a few hours, he holds the record for being the shortest-reigning monarch in Chinese history.