공손찬
For instance a unit of about 5,000 Wuhuan cavalry that usually resided in You Province (part of modern northeastern [[Hebei]] and western [[Liaoning]] Province) was deployed in Southern Jing Province (in [[Hunan]] Province) for three consecutive years. The rebellions (187-189) of Zhang Chun (張純; died 189) and Zhang Ju (張舉; died 189) in You Province in alliance with this Wuhuan cavalry unit marked the first of many such collaborations. [[Yuan Shao]] (140s–202) and [[Gongsun Zan]] (140s–199), two warlords of the [[end of the Han dynasty]], also exploited Wuhuan and Xianbei respectively in their own quests for predominance. Ironically [[Gongsun Zan]] was the commander tasked with suppressing the rebellion of Zhang Chun and Zhang Ju.