Further east the Persians came pressing in upon the Empire. They were defeated and driven back by the Syrian _dux Orientis_, duke of the East, as he was called. He was no more than a high official, appointed by Rome, but after this success against the Persians he proclaimed himself as an independent prince, the Prince of Palmyra. Zenobia, his widow, who succeeded him in his real power, though a young son was the successor to his title, maintained the independence of Palmyra, and even conquered Egypt, but again there happened that which we have seen more than once in the course of the great story--the {16} enemies of Rome prevail against her for a while, until she is provoked to put forth her full strength against them; but, once she is roused to strenuous action, they go down before her. Zenobia was defeated and brought in triumph to Rome about twenty-four years before the end of the century, and in A.D. 300 the Roman Empire stood within its bounds not greatly changed from its bounds of a hundred years before. There was, however, a real, if not a very visible, difference: the "barbarians," although for the time thrust back, had probably learnt that the Roman power was not quite invincible; and the legions guarding the frontiers had learnt that they had to rely on their own forces, without assistance from the central headquarters at Rome, for repelling the barbarians, and therefore felt less disposed to look on Rome as their master. [Sidenote: The barbarians] The condition of the Empire within its frontiers was far less prosperous at the close than it had been at the beginning of the century. We saw how the Greek thought and culture had been carried along the Roman roads to the far boundaries of the Empire. But although the barbarian armies were still kept outside those boundaries, a great many of the barbarians had come to settle within the Empire and had been taken into the legions. No doubt some of them learned the arts and the wisdom and the civilisation which the Romans had learnt from the Greeks, but on the other hand they prevented the spreading of these good lessons throughout the world. If they became somewhat "Romanised," the Roman Empire at the same time became somewhat "barbarised," by their coming in. Moreover Gaul, as we have seen, had been the scene of war, and so, too, parts of Italy itself, Greece, the Balkans, as we should call the district now, Asia Minor and Egypt. There was scarcely a corner of the Empire in which the _Pax {17} Romana_, had not been broken. Therefore the fields were waste, the population diminished, the towns were partially abandoned, trade was nearly at a standstill. Disease and lack of food followed in the train of war.