This volume unites three disparate strands of historical and legal experience. Nearly from its beginning, the Catholic Church has sought to promote peace – among warring parties, and among private litigants. The volume explores three vehicles the Church has used to promote peace: papal diplomacy of international disputes both medieval and contemporary; the arbitration of disputes among litigants; and the use of the tools of reconciliation to bring about rapprochement between ecclesiastical superiors and those subject to their authority. The book concludes with an appendix exploring a wide variety of hypothetical, yet plausible scenarios in which the Church might use its good offices to repair breaches among persons and nations.