 Despite Gao's making him emperor, however, Emperor Xiaowu tried strenuously to free himself from Gao's control, and in 534, he, aligning with the general Yuwen Tai, formally broke with Gao.When Gao advanced south to try to again take control of the imperial government, Emperor Xiaowu fled to Yuwen's territory, leading to Northern Wei's division into two (as Gao then made Yuan Shanjian the Heir Apparent of Qinghe emperor (as Emperor Xiaojing), establishing Eastern Wei).Emperor Xiaowu's relationship with Yuwen, however, soon deteriorated over Yuwen's refusal to condone his incestuous relationships with his cousins, and around the new year 535, Yuwen poisoned him to death.