Yuan Shang
Following Yuan Shao's death in 202, internal conflict broke out between his sons Yuan Shang and Yuan Tan over the succession to their father's place. Yuan Shao's followers also split into two camps – one supporting Yuan Shang and the other backing Yuan Tan. In 203, when Yuan Shang attacked Yuan Tan at Pingyuan County, Guo Tu advised Yuan Tan to make peace with Cao Cao and ally with Cao Cao to counter Yuan Shang. After Yuan Tan reluctantly agreed, Guo Tu nominated Xin Pi to serve as Yuan Tan's representative to meet Cao Cao.