Short answers, pulled from the story.
Joseph Kasa-Vubu was the first president of the Democratic Republic of the Congo, serving from 1960 to 1965. As leader of the Bakongo Association (ABAKO) party, he was one of the earliest Congolese leaders to call for independence from Belgium and played a central role in the independence movement.
Kasa-Vubu became president through an indirect election in the Senate and National Assembly after forging a coalition between his conservative ABAKO party and Patrice Lumumba's left-wing Congolese National Movement (MNC). Belgium helped organise the alliance, and Kasa-Vubu was officially sworn in on the 27th of June 1960.
Kasa-Vubu dissolved Lumumba's democratically elected government on the 5th of September 1960, accusing him without foundation of communist sympathies. He then requested that army commander Joseph-Desire Mobutu seize power and arrest Lumumba, who was subsequently handed to Moise Tshombe's Katangese forces and assassinated in January 1961.
The name Kasa-Vubu derives from an event involving Kasa-Vubu's father, a farmer in the village of Kuma-Dizi in the Bas-Congo. To appease hostile villagers, his father volunteered to undergo a poison test using a substance extracted from a kasa tree. The word "Kasa" was added to the family name in commemoration of the event.
Kasa-Vubu was deposed by a coup led by Joseph-Desire Mobutu on the 25th of November 1965. Mobutu then declared himself head of state. Kasa-Vubu was placed under house arrest before being allowed to retire to his farm in Mayombe.
Kasa-Vubu died in a hospital in Boma in 1969, four years after losing power. He was instituted as a National Hero of the Democratic Republic of Congo on the 30th of June 2020, and President Felix Tshisekedi awarded him the Grand Cordon of the Order of the National Heroes Kabila-Lumumba on the 3rd of October 2020.