Julian set out to revive the old religions and convert Rome away from Christianity. He was a bookish boy, a bit of a philosophy nerd. When he unexpectedly rose to a position of prominence, it turned out that he had a knack for military command which helped him gain popularity with the people and seize the emperorship.
I enjoyed this book because it gets you inside the head of people in a different time and place, with different thoughts and concerns than modern westerners. It also shows you how quickly the world can change. Julian lived in a time when thousands of years of tradition were changing quickly, in a blink of an eye by historical terms. These are great lessons to have in mind.