Pippin it was who administered justice in Austrasia, appointed officials and distributed dukedoms; and it was Pippin, the ~ilitary leader, who defended the frontiers threatened by Frisians, Alamanni and Bavarians.
The principal seat of the settlement was the rich plain watered by the Po and its affluents, which was in future to receive its name from them; but their power extended across the Apennines into Liguria and Tuscany, and then southwards to the outlying dukedoms of Spoleto and Benevento.
The dukedoms in the neighbourhood of the seat of power were gradually absorbed, and their holders transformed into royal officers.
To this national category belong, besides the great German dukedoms, the dukes of Normandy, and the Lombard dukes of Spoleto and Benevento, who traced their origin, not to an administrative office, but to the leadership of Teutonic war bands.
With the development of the feudal system the distinction between the official and the national dukedoms was more and more obliterated.