The Good Friday Agreement of 1998 ended a protracted violent conflict in Northern Ireland and became an international reference point for peace-building. Negotiating a Settlement in Northern Ireland, 1969–2019 traces the roots and out-workings of the Agreement, focussing on the British and Irish governments, their changing policy paradigms, and their extended negotiations, from the Sunningdale conference of 1973 to the St Andrews Agreement of 2006. It identifies three dimensions of change that paved the way for agreement: in the evolution of elite understanding of sovereignty, in the development of wide-ranging and complex modes of power-sharing, and in the interrelated emergence of substantial equality in the socio-economic, cultural, and political domains. The book combines wide-ranging analysis with unparalleled use of witness seminars and interviews where the most senior British and Irish politicians, civil servants, and advisors discuss the process of coming to agreement. In tracing the processes by which British and Irish perspectives converged to address the Northern Ireland conflict, the book provides a benchmark against which the ongoing impact of Brexit on the Good Friday Agreement can be assessed.