By the outbreak of World War I, the Protestants in Northern Ireland were afraid that Home Rule would place them under the dominion of the Catholic majority in the south. The Anglo-Irish settlement of 1920-25 partitioned Ireland into the Irish Free State (later called the Republic of Ireland) and Ulster, or Northern Ireland. Violence on both sides of the border between those who favoured the partition and those who opposed it led to the eventual dissolution of the settlement. This book is a history of Anglo-Irish relations from the time of the settlement until its demise in 1972. Mansergh discusses the interplay of concepts, interests, and personalities that shaped the settlement, the purposes it was intended to serve, the measure of its success and failure, and the circumstances of its undoing - in particular the Irish Repubic's secession from the Commonwealth in 1949 and the British government's dismantling of the local parliamentary institutions in Northern Ireland in 1972.