In the north, Augusta Trevirorum (Trèves) became the centre of Roman civilisation; under the benediction of peace agriculture, industry, and prosperity arose on all sides. The country on the left bank of the Rhine, inhabited for the most part by German tribes, was placed under a separate military administration under the name of Upper and Lower Germania. To guard the Rhenish frontier from the warlike Germans, strong permanent camps and bulwarks were erected along the river, and the army of occupation was gradually raised to eight legions. Then began the building of cities on the banks of the beautiful frontier river. Cologne was specially favoured by exemption from taxes and other privileges. Augustus devoted the same care and circumspection to the ordering of his possessions beyond the Mediterranean. The territory of Carthage and the kingdom of Numidia, formerly divided into two proconsulates, were now united to form the province of “Africa.” This was bordered on the west by the independent kingdom of Mauretania, which Augustus after some hesitation bestowed upon Juba, a loyal and devoted subject prince, till the time came for its incorporation into the world-empire in the reign of Claudius. To the east of the great Syrtis the fertile region of Cyrene stretched right to the borders of Egypt, and was combined with Crete to form a second province. If Augustus left these two provinces to be administered by the senate, he kept his own grasp all the more firmly upon the province of Egypt, which extended from the oasis of the desert to the Arabian Gulf, and from the river delta to the rocky mountains of Syene. A military advanced post in Ethiopia was withdrawn at a later time, for it was no part of Augustus’ scheme to enlarge the borders of the empire. The emperor regarded Egypt as his own special domain and watched over it jealously. No senator was allowed to travel through the country without his express permission; the administration and the supreme command of a very considerable army of occupation were in the hands of a trustworthy man who possessed his full confidence. The care which Augustus bestowed upon agriculture, irrigation, and trade was well repaid by the fertility of the country and its advantageous situation. In the first period of Roman dominion Egypt attained a height of prosperity which threw the years of the Pharaohs and Ptolemies into the shade.