This emperor, having determined to carry on the war with Persia, made a rapid transit across the Euphrates in the beginning of spring, and, passing by Edessa from hatred to the inhabitants, who had long professed Christianity, he went on to Carræ, where there was a temple of Jupiter, in which he offered up sacrifice and prayer. He then selected twenty thousand armed men from among his troops, and sent them towards the Tigris, in order that they might guard those regions, and also be ready to join him, in case he should require their assistance. He then wrote to Arsacius, king of Armenia, one of the Roman allies, to bespeak his aid in the war. In this letter Julian manifested the most unbounded arrogance; he boasted of the high qualities which had, he said, rendered him worthy of the empire, and acceptable to the gods for whom he cared; he reviled Constantius, his predecessor, as an effeminate and impious emperor, and threatened Arsacius in a grossly insulting way; and since he understood that he was a Christian, he intensified his insults, or eagerly and largely uttered unlawful blasphemies against Christ, for he was wont to dare this in every case. He told Arsacius that unless he acted according to his directions, the God in whom he trusted would not be able to defend him from his vengeance. When he considered that all his arrangements had been duly made, he led his army through Assyria.