Abstract: „The organization of the north of the ecclesiastical province of Reims took the shape, in Merlovingian times, of the uniting of ancient Roman cities under the authority of a single bishop (Arras and Cambrai, Noyon and Tournai, Boulogne and Thérouanne) that historians have interpreted as an adaptation to a society still ill christianized. This paper aims at showing that other factors may have played a part, as the concern of the monarchy of the Frankish kingdom of Neustria to ensure a better control of the region just out of the civil war (613). What we can understand of the limits between the various Merlovingian dioceses shows, however, that, on the margins, borders remained largely to be defined. This situation may have benefited monastic foundations by an aristocracy seeking a certain independance.“