Joseph Campbell (1879–1944) was a talented poet, reared in Catholic Belfast, who became a pioneer of Irish Studies in the United States. His reputation as an Irish Irelander was gained in London, but in 1921 he settled outside Dublin and soon became active in radical nationalism. In the revolutionary years he became a republican justice and local councillor in Co. Wicklow. Having opposed the Anglo-Irish Treaty, he was arrested in Bray, spending the entire Civil War interned in Mountjoy and Tintown on the Curragh. Campbell's voluminous diaries, cannily concealed from his captors, provide much more than a chronicle of events and experiences. Being the work of a skilled writer and acute observer, they offer revealing cameos of his republican colleagues, vivid notes of personal conversations, and imaginative reflections on the psychological effects of incarceration. Sympathetically edited by another distinguished poet and scholar, this selection from his diaries will fascinate all students of the Irish Civil War.