The frequency of intercourse, so far as we may judge of it from our knowledge of the network of roads, must within the civilised territory have corresponded to the density of the population. During the first century the imperial roads originated, which connected the headquarters of that time, Theveste, partly with the coast of the Lesser Syrtis--a step, having close relation to the formerly narrated pacification of the district between the Aures and the sea--partly with the great cities of the north coast, Hippo regius (Bona) and Carthage. From the second century onward we find all the larger towns and several smaller active in providing the necessary communications within their territory; this, however, doubtless holds true of most of the imperial lands, and only comes into clearer prominence in Africa, because this opportunity was made use of more diligently here than elsewhere to do homage to the reigning emperor. As to the road-system of the districts, which though Roman were yet not Romanised, and as to the routes which were the medium of the important traffic through the desert, we have no general information. [Sidenote: Introduction of camels.] But probably a momentous revolution occurred in the desert-traffic during that time by the introduction of the camel. In older times it meets us, as is well known, only in Asia as far as Arabia, while Egypt and all Africa knew simply the horse. During the first three centuries of our era the countries effected an exchange, and, like the Arabian horse, the Libyan camel, we may say, made its appearance in history. Mention of the latter first occurs in the history of the war waged by the dictator Caesar in Africa; when here among the booty by the side of captive officers twenty-two camels of king Juba are adduced, such a possession must at that time have been of an extraordinary nature in Africa. In the fourth century the Roman generals demand from the towns of Tripolis thousands of camels for the transport of water and of provisions before they enter upon the march into the desert. This gives a glimpse of the revolution that had taken place during the interval in the circumstances of the intercourse between the north and the south of Africa; whether it originated from Egypt or from Cyrene and Tripolis we cannot tell, but it redounded to the advantage of the whole north of this continent. [Sidenote: Character and culture of the people.]