During the Vietnam War, the US backed a Catholic named Ngô Đình Diệm for the leadership of their of South Vietnam. The US assumed that Diem would protect freedom of religion in South Vietnam, due to his deep faith, but instead he used his power to suppress Buddhism (which was the majority religion of South Vietnam) and promote Catholicism. The South Vietnamese government banned the flying of the Buddhist flag, leading to shooting of nine Buddhist civilians 1963, culminating in the Buddhist crisis.