This work is based on treaties between the Mamluk sultans of Egypt, Baybars (1260-1277) and Qalawun (1279-1290), and Christian rulers. The introduction describes the Arabic literary sources in which these treaties have been transmitted. Their status under Islamic law is examined, followed by a description of negotiation procedures and an account of diplomatic relations with the Christian powers. Three treaties are with the military orders, four with Beirut, Tripoli, the Latin kingdom and Tyre, and four others with Lesser Armenia, Aragon, the Byzantine Empire and Genoa. Each section has an introduction giving its historical background. The work is intended to be of use to Islamic historians and European medievalists, casting light on commercial and social as well as diplomatic relations.