Barbara Castle

Barbara Anne Castle, Baroness Castle of Blackburn, Baroness Castle, was a British Labour Party politician who was a Member of Parliament from 1945 to 1979, making her one of the longest-serving female MPs in British history. Regarded as one of the most significant Labour Party politicians, Castle developed a close political partnership with Prime Minister Harold Wilson and held several roles in the Cabinet. She is the first and, to date, the only woman to have held the office of First Secretary of State.