General James Barry Munnik Hertzog KC, better known as Barry Hertzog or J. B. M. Hertzog, was a South African politician and soldier.
He was a Boer general during the second Anglo-Boer War who became Prime Minister of the Union of South Africa from 1924 to 1939. Throughout his life he encouraged the development of Afrikaner culture, determined to protect Afrikaners from British influence. He is the only South African Prime Minister to have served under three British monarchs: George V, Edward VIII, and George VI.