This "fragmentation of powers" was not however systematic throughout France, and in certain counties (such as Flanders, Normandy, Anjou, Toulouse), counts were able to maintain control of their lands into the 12th century or later. Thus, in some regions (like Normandy and Flanders), the vassal/feudal system was an effective tool for ducal and comital control, linking vassals to their lords; but in other regions, the system led to significant confusion, all the more so as vassals could and frequently did pledge themselves to two or more lords. In response to this, the idea of a "liege lord" was developed (where the obligations to one lord are regarded as superior) in the 12th century.