The authors of this article consider bishops to have been leading figures in French Catholic reform, and regard synodal statute promulgation as a sound indicator of reforming activity. They establish an ecclesiastical map of France as it existed between the fifteenth century and the French Revolution.With this geographic base they analyze the frequency of synod statute promulgation and the changing content of synod statutes to chart the patterns of religious reform from 1390 to 1789. They discover a reforming movement that developed distinctively in France for the French, with its origins predating the Lutheran reformation by a generation. The movement extended to the mid-eighteenth century, reaching its peak in the mid- to late- seventeenth century and making an important contribution to the modernization of French attitudes.