South Vietnam establised on 26 October, 1955 after the 1955 Referendum. It was first ruled by Ngo Dinh Diem until 1963. After the 1963 coup, South Vietnam was run by a military government. It lasted until 1967. From 1967, On 1 April, 1967, the Second Republic was established. This Second Republic lasted until the Fall of Saigon when the president Duong Van Minh surrendered to Viet Cong. South Vietnam ceased to exist on 30 April, 1975. This day is also known as Black April to Vietnamese anti-communists.