Battle of Guandu
Yuan Shao and his half-brother Yuan Shu (袁術) played leading roles in the massacre of the eunuchs in September 189 and in the succeeding years both became regional warlords. Yuan Shu declared himself emperor in 197, basing his claim to the throne on descent from Emperor Shun, and died shortly afterwards. Yuan Shao dominated much of north China until he was decisively defeated by Cao Cao at the Battle of Guandu in 200. Following his death in 202, the cohesion of Ru'nan Yuan and its followers as a national power collapsed.