13‒17. Eusebius seems here to exaggerate. Cf. Episcopor. partis Majorini preces ad Constantinum, in Op. Const. Migne, col. 747.) Constantine had at once to defend Gaul against the Franks and German tribes, who had risen during the absence of Constantius in Britain (Eumen. ib., x.). In 307 Maximian, who had quarrelled with his son, crossed the Alps and allied himself with the Caesar of the West. Constantine received as wife his daughter Fausta, and with her the title of Augustus (Pan. Max. et Const. v.). For three years after marriage he found sufficient employment in consolidating his government in the West, and in wars upon the frontier of the Rhine, over which he began to build a bridge at Cologne. The seat of his court was Trèves, which he embellished with many buildings, including several temples and basilicas, and the forum. Meanwhile Galerius was seized with a painful illness, and on April 30, 311, shortly before his death, issued his haughty edict of toleration, the first of the series, to which the names of Constantine and Licinius were also affixed. Constantine remained in the West engaged in wars with the Alemanni and Cherusci, and in restoring the cities of Gaul (cf. Eumen. Gratiarum actio Flaviensium Nomine, on the restoration of the schools of Autun). He is said to have interfered by letter on behalf of the Eastern Christians whom Maximinus Daza now began to molest, and this is in itself probable (de M. P. xxxvii.). We must remember that there were now four Augusti, Licinius and Maximinus in the East; Maxentius and Constantine in the West. The two latter had for some time acknowledged one another (see below, § VI. Coins), and probably by tacit consent the four restricted themselves pretty nearly to the limits which afterwards bounded the four great prefectures. But there was little united action between them, and sole empire was perhaps the secret aim of each. Maxentius now felt himself strong enough to break with Constantine, and declared war against him. The latter determined to take the initative, and crossed the Cottian Alps, by the pass of Mont Genévre, with a force much smaller than that of his opponent. Later historians affirm that the Romans besought him by an embassy to free them from the tyrant (Zon. Ann. xiii.; Cedrenus, § 270), and this is probable, for Maxentius, by folly, insolence, and brutality had greatly alienated his subjects. Constantine had allied himself with one of the Eastern Augusti, Licinius, whom he engaged in marriage with his sister Constantia, but had to proceed against the counsels and wishes of his generals and the advice of the augurs (Pan. de Vict. adv. Maxent. ii.). After taking Turin, he rested some days at Milan, where he was received in triumph, and gave audience to all who desired it (ib. vii.). We may assume that at the same place and time, the spring or summer of 312, occurred also the betrothal of Constantia with Licinius, and the issue of a second edict of toleration to the Christians, that somewhat hard edict to which the emperors refer in the more celebrated announcement of 313 (see below § III. B. Religious Policy, and cf. Keim, Uebertritt, note 11). After taking Verona, Constantine apparently met with little resistance till within a few miles of Rome, though this is not quite consistent with the statement of Lactantius (de M. P. xliv.). He had turned the advanced guard of the enemy at Saxa Rubra, close to the Cremera, and then pressed forward along the Flaminian road to the walls of the city itself. With great rashness Maxentius had determined to give battle exactly in front of the Tiber, with the Milvian bridge behind him, about a mile from the gates of Rome. It was Oct. 26, and during the night, according to our earliest authority, Constantine was warned in a dream to draw the monogram of Christ, the 
, upon the shields of his soldiers, and now, if not before, learnt to invoke the name of Christ to help his arms (H. E. ix. 9, 12). For the different accounts of the vision see below, § V. Maxentius, meanwhile, spent the night in sacrifices and divination (Zos. ii. 16, etc.). Next morning the two armies met. That of Maxentius was totally routed, although the praetorians vigorously resisted. The fugitives crowded upon the bridge, and upon the pontoons at its side which Maxentius had devised, according to an almost incredible statement, so as to give way beneath his opponent (Eus. H. E. ix, 9; 5, 6; V. C. i. 38; Zos. ii. 15). He was himself precipitated into the river, where his body was found the next day. The victor entered Rome in triumph, and was received with great joy (Pan. de Vict. adv. M. xix.). He used his victory on the whole with moderation. Eusebius tells us that he set up a statue of himself with a spear terminating in a cross in his right hand, and an inscription to the effect that by this salutary sign (or standard) he had restored the Roman senate and people to their ancient glory and freedom (H. E. ix. 9; cf. V. C. i. 40). He now enlarged and endowed many churches in and near Rome (V. C. i. 42), and wrote the letters to Anulinus in behalf of the Catholic church in Africa which led to such important consequences (ap. Eus. H. E. x. 5, 7). From these documents it is evident that Constantine had already a strong disposition to favour the Christians, especially the Catholic body. The answers to one of them brought the case of Caecilian and the Donatists to his notice, and involved him in the affairs of the African church. He accepted the title and insignia of Pontifex Maximus, and both were borne by his successors till Gratian (Zos. iv. 36).
Period ii. 312‒324. Commencement of the cycle of Indictions, Sept. 1, 312. Constantine sole emperor of the West.—Constantine at the age of about 38 was now sole Augustus of the West. Having settled the affairs of Rome, he proceeded early in 313 to meet Licinius at Milan. There the marriage of the latter with Constantia was consummated, and the full edict of toleration, the Edict of Milan, was promulgated. The emperors then separated, Licinius to defend himself against Maximinus Daza, Constantine to guard the Rhine. Both were victorious. Licinius soon after became sole master of the East by the death of Maximus at Tarsus (Zos. ii. 17; de M. P. xlix.). The latter had followed the edict of Milan, at the behest of the other emperors, by an act of toleration of his own,
