Things seemed to be arranged in some measure to the satisfaction of Galerius, when another alarm was brought, that his son-in-law Maxentius had been declared emperor at Rome. The cause was this: Galerius having resolved by permanent taxes to devour the empire, soared to such extravagance in folly, as not to allow an exemption from that thraldom even to the Roman people. Tax-gatherers therefore were appointed to go to Rome, and make out lists of the citizens. Much about the same time Galerius had reduced the Pretorian Guards. There remained at Rome a few soldiers of that body, who, profiting of the opportunity, put some magistrates to death, and, with the acquiescence of the tumultuary populace, clothed Maxentius in the imperial purple. Galerius, on receiving this news, was disturbed at the strangeness of the event, but not much dismayed. He hated Maxentius, and he could not bestow on him the dignity of C√¶sar already enjoyed by two (Daia and Constantine); besides, he thought it enough for him to have once bestowed that dignity against his inclination. So he sent for Severus, exhorted him to regain his dominion and sovereignty, and he put under his command that army which Maximian Herculius had formerly commanded, that he might attack Maxentius at Rome. There the soldiers of Maximian had been oftentimes received with every sort of luxurious accommodation, so that they were not only interested to preserve the city, but they also longed to fix their residence in it.
Maxentius well knew the enormity of his own offences; and although he had as it were an hereditary claim to the services of his father's army, and might have hoped to draw it over to himself, yet he reflected that this consideration might occur to Galerius also, and induce him to leave Severus in Illyricum, and march in person with his own army against Rome. Under such apprehensions, Maxentius sought to protect himself from the danger that hung over him. To his father, who since his abdication resided in Campania, he sent the purple, and saluted him again Augustus. Maximian, given to change, eagerly resumed that purple of which he had unwillingly divested himself. Meanwhile Severus marched on, and with his troops approached the walls of the city. Presently the soldiers raised up their ensigns, abandoned Severus, and yielded themselves to Maxentius, against whom they had come. What remained but flight for Severus, thus deserted? He was encountered by Maximian, who had resumed the imperial dignity. On this he took refuge in Ravenna, and shut himself up there with a few soldiers. But perceiving that he was about to be delivered up, he voluntarily surrendered himself, and restored the purple to him from whom he had received it; and after this he obtained no other grace but that of an easy death, for he was compelled to open his veins, and in that gentle manner expired.