An extract on #ecchiworld
On 5 March 363, despite a series of omens against the campaign, Julian departed from Antioch with about 65,00083,000, or 80,00090,000 men, and headed north toward the Euphrates. En route he was met by embassies from various small powers offering assistance, none of which he accepted. He did order the Armenian king Arsaces to muster an army and await instructions. He crossed the Euphrates near Hierapolis and moved eastward to Carrhae, giving the impression that his chosen route into Persian territory was down the Tigris. For this reason it seems he sent a force of 30,000 soldiers under Procopius and Sebastianus further eastward to devastate Media in conjunction with Armenian forces. This was where two earlier Roman campaigns had concentrated and where the main Persian forces were soon directed. Julian's strategy lay elsewhere, however. He had had a fleet built of over 1,000 ships at Samosata in order to supply his army for a march down the Euphrates and of 50 pontoon ships to facilitate river crossings. Procopius and the Armenians would march down the Tigris to meet Julian near Ctesiphon. Julian's ultimate aim seems to have been "regime change" by replacing king Shapur II with his brother Hormisdas.
After feigning a march further eastward, Julian's army turned south to Circesium at the confluence of the Abora (Khabur) and the Euphrates arriving at the beginning of April. Passing Dura on April 6, the army made good progress, bypassing towns after negotiations or besieging those which chose to oppose him. At the end of April the Romans captured the fortress of Pirisabora, which guarded the canal approach from the Euphrates to Ctesiphon on the Tigris. As the army marched toward the Persian capital, the Sassanids broke the dikes which crossed the land, turning it into marshland, slowing the progress of the Roman army.
In 363, not long before Julian left Antioch to launch his campaign against Persia, in keeping with his effort to foster religions other than Christianity, he ordered the Temple rebuilt. A personal friend of his, Ammianus Marcellinus, wrote this about the effort:
Julian thought to rebuild at an extravagant expense the proud Temple once at Jerusalem, and committed this task to Alypius of Antioch. Alypius set vigorously to work, and was seconded by the governor of the province; when fearful balls of fire, breaking out near the foundations, continued their attacks, till the workmen, after repeated scorchings, could approach no more: and he gave up the attempt.
The failure to rebuild the Temple has been ascribed to the Galilee earthquake of 363, and to the Jews' ambivalence about the project. Sabotage by Christians is a possibility, as is an accidental fire. Divine intervention was the common view among Christian historians of the time. Julian's support of Jews caused Jews to call him "Julian the Hellene".