Zhang Zuolin
Guo Songling () (1883 – 24 December 1925) was an important general of the Manchurian Fengtian clique warlord army led by Zhang Zuolin during the Chinese Warlord Era. A republican sympathiser who briefly served under Sun Yat-Sen, he was a teacher of and an important influence on Zhang Zuolin's son, Zhang Xueliang. Citing desire to avoid civil war, he led a three-month rebellion against Zhang Zuolin which led to his defeat and execution.