Ngô Đình Diệm (; (3 January 1901 – 2 November 1963) was a former mandarin of the Nguyễn dynasty, a Prime Minister of State of Vietnam led by Bảo Đại since 1954. In October 1955, he announced a victory after a plebiscite, deposed Bảo Đại and established the first Republic of Vietnam (RVN) in South Vietnam. In November 1963, after constant religious protests and non-violent resistances, Diệm was assassinated, along with his brother, Ngô Đình Nhu, by Nguyễn Văn Nhung, the aide of the leader of The Army of Republic of Vietnam (ARVN) General Dương Văn Minh during a coup d’état sanctioned by the US. The assassination led to the end of the US-Diệm alliance and the collapse of his regime as well as the first Republic of Vietnam.