On July 8, 1966, King Mwambutsa IV of Burundi was overthrown in a coup d'état orchestrated by his own son, Prince Charles Ndizi, while the aging monarch was abroad in Switzerland. The swift takeover marked the end of a 51-year reign and reflected the turbulent power struggles that gripped Burundi as it navigated the difficult transition from colonial rule to independence. Mwambutsa IV Bangiricenge had ruled since 1915, first under German colonial administration and then under Belgian trusteeship following World War I. The Belgians governed Burundi indirectly, preserving the traditional monarchy while exerting control over the kingdom's governance, a system that kept the mwami in a delicate position of ceremonial prestige but limited practical authority.

By the mid-1960s, Burundi faced mounting pressures from ethnic tensions between the Hutu majority and the Tutsi minority, political instability, and competition for power among a new generation of ambitious leaders. Mwambutsa IV, born under German rule, had grown increasingly out of touch with the rapidly modernizing nation. At 64 years old, he had become a figurehead whose authority was challenged by younger, more assertive politicians and military officers. Prince Charles Ndizi, his son, represented a new generation willing to seize control through force. The coup occurred while Mwambutsa was receiving medical treatment in Switzerland, giving his son the tactical advantage of an absent opponent.

The 1966 coup set a pattern of instability that would plague Burundi for decades. Charles Ndizi took the throne as King Ntare V but was himself overthrown just four months later in November 1966 by Captain Michel Micombero, who established a military dictatorship. Mwambutsa IV spent his final years in exile, dying in 1977 without returning to his homeland. The events of 1966 demonstrated how the traditional monarchy, once the backbone of Burundi's social order under colonial rule, had become vulnerable to military force and contemporary politics. Burundi would not see another king on the throne after Ntare V, as the nation's rulers abandoned the institution entirely in favor of republics and military rule.