Flavius Claudius Julianus, known to modern students of history as “Julian,” was an unlikely emperor. A nephew of Constantine the Great through Constantine’s half brother Julius Constantius, there were long odds he would survive at all during the family purge that occurred following Constantine’s death.

After previously ordering the execution of his own son by his first wife, whom he may also have had executed, Constantine bequeathed the Roman empire to three sons by his second wife, Constantine II, Constans I, and Constantius II. After Constantine II died while waging war against Constans, Constans himself was killed in a revolt by the usurper Magnentius. This left Constantius II as the sole emperor of Rome, once the defeated Magnentius took his own life at the end of a three-year civil war.

Having survived this Corleone-style bloodbath, Constantius was understandably concerned about the threat his two cousins posed. After all, he was responsible not only for killing their father but much of their extended family. However, as Julian and his half brother Gallus were only children at the time, their lives were spared. They lived more or less under house arrest during their childhood but were provided a Christian education.

Ironically, talent was often a liability among Roman men of public renown. Specifically, a demonstrated ability to lead men in battle and defeat Rome’s enemies made one popular with the troops and the Roman citizenry but suspected as a rival by the emperor. Such was the fate of Julian’s brother Gallus, whom Constantius had killed after previously making Gallus a Caesar, allowing him to marry his sister, and tasking him with avenging Constans in the civil war against Magnentius.

Gallus performed far too well as a military leader and was summoned to Constantius’ court at Milan. During his journey thereto, he suddenly found the military garrisons in his path absent and was arrested and eventually executed.

Julian, on the other hand, did not immediately demonstrate any ability that could pose a threat to his cousin. After Gallus’ death, Julian was summoned to Milan where he was interrogated and detained for several months. However, partially due to the intervention of Constantius’ wife Eusebia, Julian was allowed to travel to Athens.

Julian had long wished to make this trip and immerse himself in its philosophical culture. Once there, he attended lectures, developed relationships with prominent Christian and pagan teachers and students, and was eventually initiated into the Eleusinian Mysteries. There he hope to spend his life in academic and philosophical study.

Unfortunately for Julian, his genuine love of philosophical life persuaded Constantius that he was not a rival for his throne after all, prompting Constantius to make him Caesar! Under the system established by Diocletian, Caesars were subordinate to the emperor (or emperors) who bore the title “Augustus.”
 
Julian had no desire to leave his contemplative life in Athens and had good reason to suspect his trip to meet Constantius would end similarly to Gallus’. But Constantius was sincere and the young academic was made Caesar of the West and packed off to Gaul to represent the emperor.

Julian at first took up his duties reluctantly, lamenting while performing military exercises, “Oh, Plato, what a task for a philosopher!” according to Gibbon. But in time, he became a capable administrator and military leader, defeating the barbarians who had breached the Rhine, and establishing peace once more in the province.

Of course, Julian’s demonstrated ability as a leader now provoked the same suspicion in Constantius as had Gallus’. However, with civil war once again looming, Constantius died of a fever in 361 CE, having allegedly recognized Julian as his successor before his death.

Julian was a divisive leader due to his religious and civil policies. Known as “Julian the Apostate” to the Catholic Church, Julian attempted to reestablish the empire’s traditional pagan religion and persecuted Christians. Devoted to the aesthetic life himself, he viewed the opulent court apparatus as wasteful and inefficient. He fired thousands of servants and officials and had scheming eunuchs within the court system (the “Deep State” of the day) tried and executed.

Julian was adored by his supporters, especially in the military, and hated by his detractors, especially in the Church. Equally divisive were his economic policies. Accusing wealthy merchants of price gouging, he fixed the price of grain, imported additional stores from Egypt, and forced reluctant landowners to sell at the artificially low prices.

By 363 CE, although only in his early thirties, Julian had gone from exile to absolute ruler of the Roman empire. His reign was lauded as wildly successful by his supporters, and even his political adversaries would have had to concede that the rise of this non-politician to the most powerful office in the world was extraordinary.

Then came the Persian campaign.