Tôn Thất Thuyết
Dục Đức ruled for only three days before he was deposed and sentenced to death by the same regents who had enthroned him. The reasons are unclear. Pham Van Son wrote that Dục Đức so embarrassed the court with his debauchery at the coronation that Tôn Thất Thuyết revealed the incriminating sections of Tự Đức's will. The court quickly ruled to execute him with poison for violating the mourning rules and buried him in an unmarked grave, a notably disproportionate sentence. Other contemporary historians make no mention of this episode and say that Dục Đức was not executed but rather was left to die in captivity, a likelier sequence of events considering that he lived for another three months. The true motivation for the overthrow may have been political; the regents may have feared Dục Đức would strip them of the power they enjoyed under the weak Tự Đức.