Under the Lombard system we have seen the administrative unit of the state to be the _civitas_, with its administrative head, the _dux_, at different times enjoying a greater or less degree of independence from control of the central power. We have seen the _dux_ lord as well as judge in his own jurisdiction, and standing as the successor of the military leader chosen by the people, instead of holding the position of king's servant; this place being more properly filled by the gastald, who cared for the fiscal interests of the central power, whose appointee he was. Such a form of government, it can be readily seen, left no room for any strong development of the principle of centralization, and no scope for the exercise of any decided power or even of general supervision by the central authority. The heads of the _civitates_ were the king's _judices_, it is true, and assembled to assist him in judgments at his general _placita_ in the March of each year; but they bear the character also of local lords of no mean importance, and in some cases possessed of no inconsiderable amount of power. Such a degree of individual influence--perhaps I should exaggerate if I called it individual independence--was, however, little suited to the idea of a universal centralized empire, which was the forming principle of the government of Charlemagne. While recognizing the necessity of retaining the fundamental institution of a division of the state into _civitates_, and of governing it by means of the heads of these divisions, he wished to eliminate from these officers all the characteristics of local magnates, and to reduce them to the more easily controlled position of servants, and dependents of the king. This object he accomplished most satisfactorily by changing the dukes or local lords into counts or king's men, by appointing a Count of the Palace for Italy, and by extending to that kingdom the perfectly organized system of central control by means of the _Missi Dominici_, with the workings of which in the other parts of his great empire the student of history is too well acquainted to need any description here.