This is the first full-length biography of James Griffiths, a product of the Welsh radical political tradition. Griffiths became a miner at 13 and was a conscientious objector during World War I. He rose to become President of the South Wales Miners’ Federation, the MP for Llanelli for 34 years, Chairman and then Deputy Leader of the Labor Party, and the first Secretary of State for Wales in 1964. He was a significant figure in Welsh and British politics.