Arthur Henderson was one of the first working-class MPs and held the office of Secretary of the Labour Party for nearly twenty-five years. A key minister in the first two Labour governments, he became Foreign Secretary in 1929 and received the Nobel Peace Prize for his dedicated efforts as President of the World Disarmament Conference. During the First World War and again briefly after 1931 he served as Leader of the Labour Party.

Always a moderate, 'Uncle Arthur', as he was generally known, was the embodiment of the alliance between the Labour Party and the trade union movement, a partnership that he incorporated into the fabric of the party through the 1918 constitution. His talents as a political manager were central to the Labour Party's electoral strategy and to the expansion of the constituency organisation which enabled Labour to develop from a sectional pressure group into a government party.

Central to this book is a study of Henderson's bitter and long-lasting rivalry with Ramsay MacDonald and his deep commitment to the League of Nations and the cause of world peace.