Regency
The Shunzhi Emperor died from smallpox on February 5, 1661, at the age of 24. On his deathbed he appointed four "Executive Ministers" (辅政大臣) commonly referred to as regents to "assist" his eight-year-old son Xuanye to govern the country until the young emperor reached the age of maturity at 16. The four ministers in their order of seniority were Sonin of the Yellow Banner, who apart from being chief minister of the Imperial Household Department (內務府大臣) was also nominated by Empress Dowager Xiaozhuang to head the regency. The second minister on the list was Suksaha of the White Banner. Originally a trusted deputy of Dorgon, Suksaha was politically astute enough to switch sides immediately after the former regent's death when the court was still dominated by Dorgon's associates. By the time of the Shunzhi Emperor's death he was one of the emperor's most trusted courtiers. Then came Ebilun and Oboi, both members of the Bordered Yellow Banner. The Shunzhi Emperor's succession plan set a precedence for the Qing Dynasty of nominating courtiers who owed their loyalty to the crown to "assist" a young emperor during the years of minority in running the state. This reflected the lesson learned from Dorgon's regency, when the regent grew almost too powerful for the emperor to control. Unfortunately, this system of appointing ministers to oversee the government during an emperor's minority proved not to be a very stable political device after all.
Three of the four ministers, Sonin, Ebilun and Oboi were members of the "Two Yellow Banners" (i.e. Yellow Banner and Bordered Yellow Banner) previously under the command of the Shunzhi Emperor's elder brother Hooge. Because of the personal and political rivalries between Hooge and Dorgon, all three men were persecuted at one time or another during Dorgon's regency for their Banner affiliation. However their loyalty thus proven was also key to their rapid advancement after Dorgon's death. It was a major factor in Shunzhi's choice of personnel to oversee his son's regency. However Shunzhi's arrangement heightened the already sensitive relationship between the three members of the Yellow Banners and Suksaha who belonged to the White Banner. Suksaha was a much despised figure at this point not only because he was a member of the White Banner in an imperial court dominated by the two Yellow Banners, but also because he gained the Shunzhi Emperor's trust by denouncing his former master Dorgon, an action seen by his colleagues including members of the White Banner as disloyal.
In the first years of regency, the tension between the two Yellow Banners faction and Suksaha was kept in check by an even handed Sonin and the four ministers managed to maintain a relatively peaceful and efficient working relationship. But the dynamics of the regency began to shift as Sonin's health deteriorated due to old age. As Sonin gradually took more time off on sabbatical, Oboi monopolized decision making by dominating the indecisive Ebilun and worked to sideline Suksaha during policy discussions especially on issues concerning welfare of the Manchu Eight Banners. By 1667 when Sonin realized he did not have long to live, attempted to restore some balance to the regency and also to neutralize Oboi's rapidly expanding power clique petitioned a request that the 14-year-old Kangxi Emperor assume personal rule ahead of schedule. Thus Kangxi formerly took over the reins of power in a ceremony on August 25, a month after Sonin's death. This was followed by an official decree technically downgrading the three remaining ministers to the status of "advisers" (佐政大臣) while still remaining on their posts. However even with the formal authority of office, the young Kangxi Emperor found it difficult to curb the growing power of Oboi.
Read more about this topic: Oboi