On 1 May 1971, Mangope became Chief Minister of the Bophuthatswana Legislative Assembly and retained his post following the first Bophuthatswana elections on 4 October 1972. Initially leader of the Bophuthatswana National Party, Mangope left the party following what was officially referred to as 'internal strife' and formed the Bophuthatswana Democratic Party, which then became the governing party. He became President in 1977. 