This biography of Britain’s first Labour prime minister, James Ramsay MacDonald (1866-1937), draws widely from new material in the MacDonald Papers, interviews, government documents, and private papers of political contemporaries and family members. Credited with creating a national and parliamentary Labour Party that formed two governments, MacDonald was expelled from the party when he agreed to form a National Government in 1931. The author presents a critical and often provocative analysis of the life of an illegitimate child born in humble circumstances who rose to become prime minister in 1924 and 1929-1935.