the letter was written in 361. at the time julian and his forces were marching east to face constantius. julian took the time to write a series of public letters which explained and justified his course of action. these letters were addressed to several cities of the empire which julian was attempting to win over, including (at least) athens, corinth, rome and sparta. the letter to athens happens to be the only one preserved to modern times. among other subjects, julian narrates the conditions of his proclamation to the throne by army revolt.