Gao Xingzhou
In 913, by which time Tang had fallen, and neither Li Keyong nor Liu Rengong was ruling his domain (by this time known respectively as the states of Jin and Yan) any more (Li Keyong had died in 908 and been succeeded by his son Li Cunxu as the Prince of Jin, while Liu Rengong had been overthrown by his son Liu Shouguang and put under arrest, with Liu Shouguang subsequently claiming the title of Emperor of Yan) the Jin army was launching a major attack on Yan. Gao Xinggui was then the prefect of Wu Prefecture (武州, in modern Zhangjiakou), and, unable to stand the attack of the Jin general (Li Cunxu's adoptive brother) Li Siyuan, surrendered Wu to Li Siyuan. When the major Yan general Yuan Xingqin heard this, he attacked Wu Prefecture. Gao Xinggui then sent Gao Xingzhou as a hostage to Li Siyuan and sought emergency aid. Li Siyuan, with Gao Xingzhou serving as his guide, was subsequently able to defeat Yuan, forcing Yuan's surrender. Subsequently, both Yuan and Gao Xingzhou remained as officers under Li Siyuan, with Gao and Li Siyuan's adoptive son Li Congke often serving as commanders of Li Siyuan's personal guards.