18. At this time Eusebia, the queen, who herself was barren all her life, began to plot against Helena, the sister of Constantius, and wife of the Cæsar Julian, whom she had induced to come to Rome under a pretence of affection, and by wicked machinations she induced her to drink a poison which she had procured, which should have the effect, whenever Helena conceived, of producing abortion. 19. For already, when in Gaul, she had borne a male child, but that also had been dishonestly destroyed because the midwife, having been bribed, killed it as soon as it was born, by cutting through the navel-string too deeply; such exceeding care was taken that this most gallant man should have no offspring. 20. But the emperor, while wishing to remain longer in this most august spot of the whole world, in order to enjoy a purer tranquillity and higher degree of pleasure, was alarmed by repeated intelligence on which he could rely, which informed him that the Suevi were invading the Tyrol, that the Quadi were ravaging Valeria,[65] and that the Sarmatians, a tribe most skilful in plunder, were laying waste the upper Moesia, and the second Pannonia. And roused by these news, on the thirtieth day after he had entered Rome, he again quitted it, leaving it on the 29th of May, and passing through Trent he proceeded with all haste towards Illyricum. 21. And from that city he sent Severus to succeed Marcellus, a man of great experience and ripe skill in war, and summoned Ursicinus to himself. He, having gladly received the letter of summons, came to Sirmium, with a large retinue, and after a long deliberation on the peace which Musonianus had reported as possible to be made with the Persians, he was sent back to the East with the authority of commander-in-chief, and the older officers of our company having been promoted to commands over the soldiers, we younger men were ordered to follow him to perform whatever he commanded us for the service of the republic. XI. A.D. 357. § 1. But Julian, having passed his winter at Sens, amid continual disturbance, in the ninth consulship of the emperor, and his own second, while the threats of the Germans were raging on all sides, being roused by favourable omens, marched with speed to Rheims, with the greater alacrity and joy because Severus was in command of the army there; a man inclined to agree with him, void of arrogance, but of proved propriety of conduct and experience in war, and likely to follow his lawful authority, obeying his general like a well-disciplined soldier. 2. In another quarter, Barbatio, who after the death of Silvanus had been promoted to the command of the infantry, came from Italy by the emperor's orders, to Augst, with 25,000 heavy-armed soldiers.