A regular and uninterrupted communication was, under these princes, beginning to be firmly established with all parts of the Roman empire; and the intercourse which then existed between the eastern and western parts of Northern Africa was much greater than that which had obtained under the governments of the Greeks and Carthaginians. The numerous native tribes who inhabited the coast were perpetually at variance with their foreign invaders, and ever ready to avail themselves of the slightest opportunity of harassing their oppressors, or of recovering their ancient inheritance. It must also be observed, that, however worthless and insignificant the regions of the Syrtis might possibly appear, to the inhabitants of more favoured countries, there are parts of them which must always have been eagerly coveted by the wanderers of the desert which bounds them to the southward; since the advantages which they are occasionally found to afford, though consisting merely in a little fresh water, and a few spots of scanty vegetation, would naturally be objects of great attraction to those who had seldom the opportunity of finding either. From the sudden, but unskilful, attacks of these people, the forts and stations of the Syrtis would have been sufficient defence; and they would also have been more convenient for the troops than the usual Roman encampment, greatly contributing at the same time, to facilitate the communication of one part of the country with another, by ensuring a good supply of water, and serving as depôts for stores and provisions. We must not, however, venture decidedly to assert, that the Syrtis was unprovided with buildings of this nature before the occupation of the country by the Romans; for, without mentioning those of Euphrantas and Automala, we find that castles were in use among the natives of Northern Africa before that period; and if they are known to have been previously erected in other parts of the coast, they might equally have existed in the Syrtis[21]. Many buildings of this nature appear to have remained in a tenable state long after the conquest of Africa by the Mahometans; for they are frequently mentioned by Arab writers as having been occupied by the natives; and wells still continued to be found within the works, which could not be approached without the consent of the garrison.