 Julian's rise to Augustus was the result of military insurrection eased by Constantius's sudden death.This meant that, while he could count on the wholehearted support of the Western army which had aided his rise, the Eastern army was an unknown quantity originally loyal to the Emperor he had risen against, and he had tried to woo it through the Chalcedon tribunal.However, to solidify his position in the eyes of the eastern army, he needed to lead its soldiers to victory and a campaign against the Sassanid Persians offered such an opportunity.