Mainly because of the First World War, the Vatican in its efforts on behalf of peace became “a new force in international affairs”, as John Pollard observes. His book is a welcome alternative to the surveys of papal history that have appeared in recent years. The focus on only three pontificates – those of Benedict XV, Pius XI, and Pius XII – draws our attention to the tumultuous crucible of international conflict and fraught church-state relations from which the modern papacy emerged as a recognised diplomatic force.Pollard’s book portrays the three popes as diplomats as well as pastors. The integration of these two papal roles as well as the global milieu of papal concern are commendable features of the book. The popes adopted a vigorous and consistent miss