Hand-in-hand with the growth of episcopal organization we see another term coming into use in connection with the same land division, and this also is an administrative one, but of the church simply, and only made use of by conversion or carelessly when applied to a civil area. I mean the _districtus_, which term is properly applicable only to the jurisdiction of a bishop, and designates the limits of his episcopal power, that is, his diocese. The reasons for this term being used in later times occasionally for the civil division, the _civitas_, are twofold. They result, firstly, from the confusion which arose between matters of civil and ecclesiastical jurisdiction, when political power was given to a large number of the bishops, and when they united to their religious duties as pastor, the judicial and sometimes even some of the military duties of _comes_ and _judex_. And secondly, in the important fact that in almost all cases the boundaries of a bishop's diocese coincided more or less exactly with the limits of the authority of the state officers; so that the division which should be called a _civitas_ or _territorium_ from the point of view of civil government, should be called a _districtus_ from that of ecclesiastical government. Where we find at once the most important and, if not rightly understood, the most perplexing traces of the survival of the old Roman municipal system, is in this matter of territorial boundaries. According to the Roman system, as we have seen, the city was the important administrative unit, and each city was surrounded by a belt of rural lands, more or less large according to the size and importance of the city itself. This of course resulted in a division of the whole country into a number of districts whose boundaries were definitely marked, perhaps even jealously guarded. Now, when the Lombards took possession of the country, while they rejected the principle of the municipal unit, as foreign to the character and instincts of their race, they could not fail to see the practical utility of using, and the actual difficulty of overthrowing, a system of land division which custom and authority had united in rendering alike definite and convenient. What was the result? They made use of the old boundary lines, leaving their limits, as far as we can judge, untouched, and substituted as the fundamental principle of their administration, in place of the Roman idea of the _municipium_, the thoroughly Teutonic idea of the _civitas_ or country district. Coincident with these time-honored boundaries which served to mark the limits of the jurisdiction of the duke and the _judex_, are to be found those of the ecclesiastical power, of the bishop's diocese.