Free The Calendar by David Ewing Duncan

ruthless and never hesitated to plunge the empire into war to further his own ambitions. But he also repaired imperial highways and established an efficient messenger network, revamped the legal system, built magnificent basilicas, aqueducts, monuments and churches, and mostly kept the peace. He also sought to transform the imperium itself, completing a shift begun by Aurelian and Diocletian toward an oriental-style monarchy where kings ruled not by the grace of the Senate and the people, or even the army, but as all-powerful despots who claimed to be chosen by the gods (or God).
    Aurelian (ruled 270-275) had launched this transformation by founding a cult of a monotheistic sun-god in Rome during the 270s, a precursor to the imposition of Christianity. Building a resplendent new temple to the sun in Rome, Aurelian announced that the sun-god had made him emperor, not the Senate; a transformation cut short by his assassination shortly thereafter. Diocletian (ruled 284-305) furthered this eastern tilt by also embracing the cult of the sun and by dividing the empire into eastern and western halves, with the main centre of power under his control in the East. He gave up the traditional purple toga of the emperor for sumptuous silk robes and jewel-encrusted belts and shoes; and, for the first time since the early days of the Latin kings, a Roman head of state donned a crown. Constantine would complete this easternification by choosing Byzantium as the site for his new capital, Constantinople. Strategically located near the empire’s richest provinces, it was within striking distance of both the western and eastern frontiers.
    Constantine would also adopt one of the East’s chief religions, reversing 350 years of largely secular rule--symbolized by Caesar’s calendar--in a move that would soon fuse the political and military might of a still-potent empire with what would become an even more potent state religion.
    At first it was not entirely clear which religion. During these troubled time Romans embraced several popular sects, most of them from the East--everything from a pseudo-religious brand of Neo-Platonism to Christianity and the worship of the sun. Keenly aware of this diversity, the always expedient Constantine seemed willing to embrace virtually any religion that might serve his political needs, despite his story--told much later--about the Christian god and the flaming cross of gold at the Mulvian Bridge. In fact, at the time he credited his victory over Maxentius to more than one god.
    To please the pagans of Rome, he erected the Arch of Constantine, which dedicates his triumph to Rome’s old deities--and remains one of the best-preserved and most imposing triumphal arches in present-day Rome. Constantine also flirted with the popular cult of the sun-god Mithras at the time of the battle since the Mithraists also held sacred a symbol similar to a cross. Certainly such a twin billing would have pleased the large numbers of both Mithraists and Christians in his army.
    Only over the course of several years did Christianity gradually win out, perhaps because the Christians offered a more effective power base, or because Constantine found the tenets and organizational structure of the Christian Church easier to co-opt and merge into the existing imperial structure. Another, simpler reason may have involved Constantine’s mother, the British-born Helena (248-328), a former barmaid and a long-time Christian who was mistress (and possibly a first wife) to Constantine’s father. A formidable woman who seldom left her son’s side, Helena lobbied hard for the Christian god, receiving generous sums from her son to build dozens of churches from Judea to Gaul, including the still-standing Church of the Nativity in Bethlehem and the Church of the Holy Sepulchre in Jerusalem. Constantine himself hedged on a full personal commitment to his own state religion until 337, when he was finally baptized on his deathbed.
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