A member of the Union for National Progress (UPRONA), he previously served as Minister of the Interior from September to October 1961.
[2] Following the death of his father in 1930 and his protests over the former's appointed successor, the Belgian Residency forced him into exile with his brothers in Tanganyika.
[1] The marriage was part of a deal struck by Muhirwa with the monarchy to assume his father's chiefdom, with the assistance of Chiefs Ntitendereza and Barusasiyeko.
[8] At the Legislative Assembly's session on 22 October Muhirwa, citing the distraction of "recent events", declined to offer a government program and the body sat aimlessly for the next few months.
[12] The death of Rwagosore stoked divisions in UPRONA, and fueled a rivalry between Muhirwa and a Hutu politician, Paul Mirerekano.
A caucus of several UPRONA leaders met on 4 July 1962 to settle the dispute and confirmed Muhirwa's ascension to the party presidency.
[14] Mirerekano refused to concede, and at the Mwami's intervention, an UPRONA mass congress was held in September, which led to both men being assigned vice presidencies in the party.
Muhirwa led a delegation to the United Nations headquarters in February 1962 to discuss the terms of Burundi's impending independence.
[19] He also signed the promulgation order for the new Constitution of the Kingdom of Burundi alongside Mwambutsa and Minister of Justice Claver Nuwinkware.
[26] Faced with growing parliamentary opposition and the monarchy's interventions, Muhirwa gave Mwambutsa his resignation that day.
[25] Despite this, Muhirwa retained his position in UPRONA and remained influential in national politics as the leader of the Casablanca group.
He was later released and on 28 November 1967 appointed to a sinecure position with the Bujumbura port authority,[29] serving on its board of directors.