Chen Youliang

Chen Youliang (traditional Chinese: 陳友諒; simplified Chinese: 陈友谅; pinyin: Chén Yǒuliàng)(1320 – August 23, 1363) was Cheng Kun's apprentice. He served the Beggars' Sect as a spy for his master, and manipulated Song Qingshu into betraying Wudang. He defected to the Ming Cult after Cheng Kun's defeat but betrayed the cult eventually. 
In 1357, Chen proclaimed himself "King of Han" in Jiangzhou (江州; present-day Jiujiang, Jiangxi), and emperor the next year after Xu Shouhui died. His era name, as well as his empire's name, was "Dahan" (大漢; literally "Great Han"). For 1359 to 1363 Chen's fleet was the strongest on the upper Yangtze River. His power was at least as great as that of another rebel state, Wu, led by Zhu Yuanzhang, founder of the Ming Dynasty.
In 1360 the Dahan fleet and army began a long war against Wu forces - based at that time in Jiqing (present-day Nanjing) and was later renamed "Ming" in 1368. An attack on the Wu capital was defeated thanks to excellent Wu intelligence (likely due to the defection of part of the Dahan fleet earlier in the year). 
The war continued till the climactic Battle of Lake Poyang where the Wu fleet narrowly defeated the larger fleet of Dahan after three days of fighting. 
A month after the battle at Lake Poyang, the Dahan fleet tried to break out from Lake Poyang, during the resulting ship battles Chen was killed (he was alleged to have died from an arrow wound in the head). He was 43 years old at the time of his death.
As his crown prince Chen Shan (陳善) had been captured, Chen Youliang was succeeded by his second son, Chen Li, who was soon attacked by the fleet and army of Wu. The conquest of Dahan took an additional two years but by April 1365 the Dahan empire was gone and all its lands were now part of now part the Wu power base.