Modu Chanyu
The Wuhuan continued to support the Yuan clan after Yuan Shao's defeat at the Battle of Guandu against Cao Cao, shortly after which Yuan Shao died. Subsequently, Yuan Shao's oldest son Yuan Tan and youngest son Yuan Shang fought among themselves in a succession feud, which Cao Cao exploited for himself. Soon Yuan Tan was killed in a battle against Cao Cao and Yuan Shang had to flee to his second brother, Yuan Xi, in You Province. The Yuan brothers in You Province then suffered a mutiny, and fled further north to seek protection from the Wuhuan. The Wuhuan at this time had been united under the military leadership of Tadun, and his apparent strength prompted rumours that he was seeking to emulate Modu Chanyu of the Xiongnu and Tanshihuai () of the Xianbei in creating a hegemony over the northern nomadic tribes. With the arrival of the Yuan brothers, accompanied by a considerable number of their followers, Tadun had gained command of a combined Wuhuan and Chinese force that was said to have numbered up to 300,000.