An illumination of the life of diplomat Roger Casement. At the time of his execution for treason in 1916, few were aware who Roger Casement was or what he represented. Since then, he has been lauded for his investigations into Belgian brutality in the Congo Free State and human rights abuses in the Peruvian rubber industry, but much else about him has remained obscured behind speculation about his sexuality and secret Irish revolutionary activity while in service of the British Empire. As such, his place in history has been ill-defined and his involvement in the waging of war followed by the delicate negotiation of peace; his republicanism perceived variously as an eccentric enthusiasm and as a threat to the British Empire; his contemporary legacy overshadowed by the Black Diaries of disputed legitimacy, detailing alleged liaisons with young men. In Casement, Angus Mitchell illuminates a life shrouded in mystery, which operated in the conflicting spheres of British foreign diplomacy and Irish revolutionary activity. Considering Casement’s rebellious nature, Mitchell asks if it was motivated as much by his “incorrigible” Irishness as by his exposure of the appalling crimes against humanity that he witnessed in Africa and South America. Most significantly, Casement demonstrates that his legacy cannot be ascribed to just one cause, whether as a critic of global colonialism or as a founding father of the modern Irish nation-state. Casement’s true commitment was to a universal understanding based on humanity, tolerance, and justice.