"I know that I am aware that I have no outstanding qualities, neither by nature nor by subsequent acquisition, except a love of philosophy." Thus said the Roman emperor Julian the Apostate (331-363) in a letter to the philosopher Themistius. Grandson of Constantine I, from whom he fled to avoid the emperor's conspiracy against his relatives, Julian was raised in Christianity from a young age. He studied in Rome, then converted to paganism and embraced the wisdom of the great philosophers of the past, effectively living as a pagan in the Roman Empire, which was increasingly inclined toward the cult of Christianity, to the detriment of the ancient gods and beliefs.

Raised to the rank of "Caesar" in 355, he was sent, albeit with limited powers, to administer the remote province of Gaul, where he nevertheless managed to distinguish himself through good governance. His military and political successes then convinced him to rebel against Emperor Constantius, who had actually sent him to Gaul to "death under the purple [the colour of Caesar's robes]," and he succeeded in being acclaimed sole emperor in 361. Julian, following the teachings of the great classical philosophers, condemned government based on hereditary right and despotism, where a single citizen was "master of all the others. For if all are equal by nature, all necessarily have equal rights, and therefore the ruler (himself) must be better (more morally just) than the ruled. In parallel, Julian also wrote philosophical works, among which stood out a comedic treatise on the beard, a metaphor for ancient, pagan wisdom contrasted with Christian rigidity (Julian wore a philosopher's beard, as in ancient Greece, a practice frowned upon by Christians in his time).

From an administrative standpoint, the new emperor promoted a policy aimed at streamlining bureaucracy, building roads and public works, and promoting the well-being of the poor by lowering grain prices, without displeasing the ruling classes, to whom he bestowed public offices. He fought at the forefront for separating the Christian faith from teaching careers, upholding the duality of Romanitas and Hellenism as a prerequisite for the empire's health. In this regard, in 362, he issued an edict declaring the incompatibility between the Christian and Hellenistic visions.

After Julian died in the war in 363, people remembered him ambiguously for his pagan faith and good governance.