Yuan Shao, the powerful warlord of the north, had been decisively defeated by his southern neighbour Cao Cao in the Battle of Guandu in 200 and died two years later in frustration. Despite the defeat, the Yuan power bloc was by no means eliminated, for Yuan Shao was survived by his three sons Yuan Tan, Yuan Xi, and Yuan Shang; together with their cousin Gao Gan, the Yuan family still held on to the provinces of Ji, Qing (青), Bing, and You. The Yuan brothers were not on good terms, however - Yuan Tan, the oldest, contested the succession of his younger brother Yuan Shang, who was preemptively made heir by his supporters Shen Pei and Pang Ji, while the second son Yuan Xi was content with controlling the northernmost You Province and stayed out of his brothers' conflict. In the winter of 202,