This book is the first comprehensively researched study of the life and thought of Irish-born William Thompson (1778–1833), who is regarded by historians of socialist thought as the most influential theorist to emerge from the Owenite movement in early 19th-century Britain and Ireland. His work on the distribution of wealth was used by Marx, and he also became a key figure in the history of feminism. Fintan Lane outlines Thompson’s personal and political context as well as examining his social, political and economic thought. Part One covers his family, social and Irish background and his engagement with radical ideas, including his collaboration with Jeremy Bentham. Part Two focuses on his time as a leading thinker in the early socialist movement, while the Epilogue discusses the notorious dispute over his will, his subsequent influence and how he has been regarded since his death. Bringing to light new facts about Thompson as well as correcting previous misunderstandings about his life and context, this long-overdue study of an important and influential thinker will appeal to historians of modern Britain and Ireland, of political economy and those interested in the history of ideas more broadly.