He subsequently worked for the Belgian Residency of Urundi, served as the private secretary of Mwami Mwambutsa IV, and headed the Nyabikere chiefdom.
[6] His death stoked divisions in UPRONA, and fueled a rivalry between Hutu politician Paul Mirerekano and the new Ganwa prime minister, André Muhirwa.
[8] At Mwami Mwambutsa's intervention, an UPRONA mass congress was held in September 1962 to resolve the leadership dispute, which led to both Mirerekano, Muhirwa, and Siryuyumunsi being assigned vice presidencies in the party.
[10] The Assembly had been out of session at the time, and when it reconvened on 14 May, its members intensively debated the election of a presiding officer.
[12] He actively encouraged Burundi to recognize Communist China, and the following year he led a three-person parliamentary delegation to there and the Soviet Union.
Siryuyumunsi joined the other members of the Assembly bureau in protesting perceived constitutional violations by the monarchy in February and March.
[4] While discussions on the creation of a new government took place, Hutu politician Gervais Nyangoma offered himself as a candidate to be named prime minister.
In August the Mwami rejected consideration of Nyangoma for the premiership, surprising Hutu deputies in the Assembly.
He dismissed the Biha government and appointed a new one led by Army Captain Michel Micombero as prime minister.
[21] Soon thereafter conflict arose between Ntare, who wished to actively rule, and the new government and its supporters, eager to implement progressive reforms without interference from the crown.