On 8 July 1966, a coup d'état took place in the Kingdom of Burundi. The second in Burundi's post-independence history, the coup ousted the government loyal to the king (mwami) of Burundi, King Mwambutsa IV, who had gone into exile in October 1965 after the failure of an earlier coup d'état.
The first coup attempt had been led by members of the Hutu ethnic group and was provoked by rising ethnic tensions between the Hutu and Burundi's Tutsi ruling class. The July 1966 coup was an extreme Tutsi counter-reaction against what they saw as Mwambutsa's dangerous moderate tendencies in trying to balance Hutu and Tutsi demands in government.
In March 1966, shortly after going into exile, Mwambutsa had delegated his royal powers to his son, Prince Charles Ndizeye. On 8 July 1966, forces loyal to Ndizeye overthrew the pro-Mwambutsa government of Léopold Biha and established Ndizeye as mwami. In September, Ndizeye was formally crowned, taking the royal title Ntare V. Ntare promised to Burundi strong leadership, anti-corruption measures, and a new constitution. On 11 July, Ntare promoted Michel Micombero, a Tutsi army officer who had played a major role in the coup, to the post of Prime Minister. Less than five months later Micombero led a third coup d'etat on 28 November which ousted Ntare after just six months on the throne. Micombero abolished Burundi's monarchy and declared the nation a Republic. This allowed Micombero to establish a one-party military dictatorship which would last until his own overthrow in 1976.
Ntare V fled into exile but returned to the country from Uganda in 1972, at which time he was assassinated under circumstances that have yet to be fully explained.