According to the rules of the new constitution, Constantius and Galerius assumed the title of Augustus, and nominated Maximin and Severus as Cæsars. The elaborate machinery devised by Diocletian at once broke down. Galerius, who was supported by Severus, intrigued for the possession of the whole Roman world. Constantine, the son of Constantius, on account of his popularity with the army and the people, excited his suspicion, and only the flight of Constantine saved him from death. He made his way to Gaul, and, after taking part in a campaign with his father against the Caledonians, received the title of Augustus in the imperial palace at York on the death of Constantius. Civil war once more raged. Maxentius, the son of Maximian, was declared Emperor of Rome, and, with the assistance of his father, who broke from his retirement, defended his title against Severus, who was taken prisoner at Ravenna and executed at Rome in February 307. Galerius, who had raised Licinius to fill the post vacated by the death of Severus, invaded Italy to reestablish his authority, but, after threatening Rome, was compelled to retire. There were now six emperors. Maximian and his son Maxentius and Constantine in the West; in the East, Gelerius, Maximin, and Licinius. The second resignation of Maximian, and his renewed attempt to seize the imperial power by seducing the soldiers of Constantine, and his subsequent execution at Marseilles in February 310, reduced the number to five. Galerius died of a lingering disorder in the following year, and the civil war that broke out between Maxentius and Constantine, culminating in a battle near Rome in 312, placed the sceptre of the West in the hands of the son of Constantius. In the East, the alliance between Licinius and Maximin dissolved into discord, and the defeat of the latter on April 30, 313, ended in his death three or four months later. The empire was now divided between Constantine and Licinius, and the ambition of the two princes rendered peace impossible. In the years 315 and 323 civil conflict broke out, ending, after the battle of Adrianople and the siege of Byzantium, in a culminating victory for Constantine in the field of Chrysopolis, in September. Licinius, taken prisoner, laid himself and his purple at the feet of his lord and master, and was duly executed. By successive steps, from his first assuming the purple at York, to the resignation of Licinius, Constantine had reached the undivided sovereignty of the Roman world. His success contributed to the decline of the empire by the expense of blood and treasure, and by the perpetual increase as well of the taxes as of the military establishments. The foundation of Constantinople and the establishment of the Christian religion were the immediate and memorable consequences of this revolution. * * * * * Decline and Fall of the Roman Empire--II _I.--Decay of the Empire under Constantine_