During Emperor Fei's reign
Pursuant to Emperor Wenxuan's will, the government was in the hands of several of his trusted officials – Yang Yin, Gao Guiyan (高歸彥) the Prince of Pingqin, Yan Zixian (燕子獻), and Zheng Yi (鄭頤). Gao Yan, while respected by the people, was not given great power, and while Grand Empress Dowager Lou had some desire to have Gao Yan made emperor instead, there was insufficient support at the time, and Yang, in fear that Gao Yan and another brother of Emperor Wenxuan, Gao Zhan the Prince of Changguang, would try to take power, took steps to curb their authorities. Meanwhile, Gao Yan's own supporters, citing the example of the Duke of Zhou, were suggesting to him that he should take power as the young emperor's uncle, and while Gao Yan initially rejected such overtures, he was watching the political scene carefully.
As Emperor Fei took the throne while he was attending to his father's deathbed at the secondary capital Jinyang (晉陽, in modern Taiyuan, Shanxi), when he proceeded to the capital Yecheng (鄴城, in modern Handan, Hebei) in spring 560, it was initially believed that Gao Yan or Gao Zhan would be put in charge of Jinyang—then perhaps the most militarily secure city in the empire; instead, by the arrangements of Yang and his associates, the two princes were ordered to accompany the young emperor to Yecheng.
Once the imperial train arrived at Yecheng, the situation became even more tense, as an associate of Yang's, Kezhuhun Tianhe (可朱渾天和), was convinced that Emperor Fei would not be safe in his reign unless his two uncles were killed, and alternatively, Yan Zixian considered putting Grand Empress Dowager Lou, who still wielded much power as the clan matriarch, under house arrest, and forcing her to turn her authorities to Empress Dowager Li. Meanwhile, the ambitious Yang was carrying out a governmental reorganization scheme to trim unnecessary offices and titles and to remove incompetent officials. The officials who were hurt by Yang's actions became disaffected and largely hoped that Gao Yan and Gao Zhan would take action and began to encourage them to do so. In spring 560, Yang considered sending Gao Yan and Gao Zhan outside the capital to be provincial governors, but Emperor Fei initially disagreed. Yang wrote a submission to Empress Dowager Li to ask her to consider, and she consulted her lady in waiting Li Changyi (李昌儀), who leaked the news to Grand Empress Dowager Lou. She informed the two princes, and they set up an ambush, with Gao Guiyan and the generals Heba Ren (賀拔仁) and Hulü Jin, at a ceremony where Gao Yan was to be named to a ceremonial post. Yang, Kezhuhun, Yan, Zheng, and Song Qindao (宋欽道) were all captured and severely battered. Gao Yan and Gao Zhan then entered the palace and publicly accused Yang and his associates of crimes; Yang and his associates were executed, and Gao Yan took control of the government. He soon went to take up post at Jinyang, controlling the government remotely.
Gao Yan's advisors, headed by Wang Xi and Zhao Yanshen (趙彥深), then suggested that he take the throne himself—noting to him that his actions in killing Yang and his associates meant that when Emperor Fei was grown, he would never be able to have a cordial relationship with Emperor Fei. Gao Yan agreed, and although initially Grand Empress Dowager Lou found the action inadvisable, she finally agreed. In fall 560, she issued an edict deposing Emperor Fei and making Gao Yan emperor (as Emperor Xiaozhao); however, in the edict, she sternly warned Emperor Xiaozhao to make sure that nothing would happen to Emperor Fei, who was demoted to the rank of Prince of Ji'nan. Grand Empress Dowager Lou became again known as Empress Dowager Lou, while Empress Dowager Li was given the title of Empress Wenxuan.