Emperor Julian the Apostate! (AD 332 - AD 363)
"He is clearly Rome's second ever philosopher-ruler, after the great Marcus Aurelius. But if Marcus Aurelius was weighed down by war and plague then, Julian's greatest burden was to be that he belonged to a different age. Trained classically, learned in Greek philosophy he would have made a fine successor to Marcus Aurelius. But those days had gone, now this distant intellect seemed out of place, at odds with many of his people, and certainly with the Christian elite of society. "
--nice bio by Gore Vidal, too.