Flavius Claudius Julianus, or Julian the Apostate, ruled Rome as sole emperor for just a year and a half, from 361 to 363, but during that time he turned the world upside down. Although a nephew of Constantine the Great, the first Christian emperor of Rome, Julian fought to return Rome to the old gods who had led his ancestors to build their vast empire.

As emperor, Julian set about reforming the administration, conquering new territories, and reviving ancient religions. He was scorned in his time for repudiating Christianity and demonized as an apostate for willfully rejecting Christ. Through the centuries, Julian has been viewed by many as a tragic figure who sought to save Rome from its enemies and the corrupting influence of Christianity. Christian writers and historians have seen Julian much differently: as a traitor to God and violent oppressor of Christians. Had Julian not been killed by a random Persian spear, he might well have changed all of history.