Abstract: This is a study of marriage litigation (with some reference to sexual offenses) in the archiepiscopal court of York (1300–1500) and the episcopal courts of Ely (1374–1381), Paris (1384–1387), Cambrai (1438–1453), and Brussels (1448–1459). All these courts were, for the most part, correctly applying the late medieval canon law of marriage, but statistical analysis of the cases and results confirms that there were substantial differences both in the types of cases the courts heard and the results they reached. Marriages in England in the later middle ages were often under the control of the parties to the marriage, whereas those in northern France and southern Netherlands were often under the control of the parties' families and social superiors. Within this broad generalization the book brings to light patterns of late medieval men and women manipulating each other and the courts to produce extraordinarily varied results. • Applies fairly rigorous statistical methods to the records of the medieval ecclesiastical courts. • Explores in detail and comparatively the patterns of litigation in two different geographical areas in roughly the same time period. • Integrates our knowledge of medieval canon law and institutions with what can be learned about the social background of cases.