The provisions in the will of Augustus concerning the boundaries of Roman empire came to be disregarded. The Rhine and the Danube, indeed, formed the Northern frontier of the Empire in continental Europe, and mountains and desert bordered the Empire on the east and the south and the Atlantic Ocean on the west. Yet, in spite of the fact that the Danube formed a natural boundary that was relatively secure in Eastern Europe, two areas remained vulnerable and caused the strategists of Rome great anxiety: the Bohemian plateau on the middle course of the Danube and the Transylvanian plateau on the lower. The first was never to be conquered; the second, where the centre of the Dacian state was established, became too dangerous and the Empire had to concentrate all its strength for its conquest (FIG. 1).