This book situates the history of Trinity College Dublin within the great upheavals and changes that were taking place in Ireland and the wider world in the transformative period between 1912 and 1923. The period saw Trinity and its environs profoundly changed. The book uses Trinity as a way of exploring some of the central themes and tensions of these years, themes that are usually examined separately: Irish involvement in the First World War; the Easter Rising of 1916; the violent struggle for Irish independence; the end of the Civil War; and the establishment of the Irish Free State in 1922. It views these events through the prism of the university's development, arguing that these contexts cannot be divorced from one another. Trinity was at the centre— physically, intellectually, symbolically—of these seismic events in local, national and international history, and each had a great impact upon the institution and its development in the twentieth century. Cumulatively, they transformed the university by 1923.