This is an interpretation of the lifelong preoccupation of Eamon de Valera, a revolutionary nationalist who defined his goal in the 1916 Easter Rising in Dublin and spent the rest of his long career working for the achievement of a united, sovereign Irish Republic. It examines both his own policy and his political legacy on a question which still lies at the heart of modern Irish politics and Anglo- Irish relations. The author was winner of the Christopher Ewart-Briggs Memorial Prize.