The city, or rather the fortress, of Maogamalcha, which was defended by sixteen large towers, a deep ditch, and two strong and solid walls of brick and bitumen, appears to have been constructed at the distance of eleven miles, as the safeguard of the capital of Persia. The emperor, apprehensive of leaving such an important fortress in his rear, immediately formed the siege of Maogamalcha; and the Roman army was distributed for that purpose into three divisions. Victor, at the head of the cavalry, and of a detachment of heavy-armed foot, was ordered to clear the country, as far as the banks of the Tigris, and the suburbs of Ctesiphon. The conduct of the attack was assumed by Julian himself, who seemed to place his whole dependence in the military engines which he erected against the walls, while he secretly contrived a more efficacious method of introducing his troops into the heart of the city. Under the direction of Nevitta and Dagalaiphus, the trenches were opened at a considerable distance, and gradually prolonged as far as the edge of the ditch. The ditch was speedily filled with earth; and, by the incessant labour of the troops, a mine was carried under the foundations of the walls, and sustained, at sufficient intervals, by props of timber. Three chosen cohorts, advancing in a single file, silently explored the dark and dangerous passage, till their intrepid leader whispered back the intelligence, that he was ready to issue from his confinement into the streets of the hostile city. Julian checked their ardour, that he might insure their success; and immediately diverted the attention of the garrison by the tumult and clamour of a general assault. The Persians, who, from their walls, contemptuously beheld the progress of an impotent attack, celebrated, with songs of triumph, the glory of Sapor; and ventured to assure the emperor, that he might ascend the starry mansion of Ormuzd, before he could hope to take the impregnable city of Maogamalcha. The city was already taken. History has recorded the name of a private soldier, the first who ascended from the mine into a deserted tower. The passage was widened by his companions, who pressed forward with impatient valour. Fifteen hundred enemies were already in the midst of the city. The astonished garrison abandoned the walls, and their only hope of safety; the gates were instantly burst open; and the revenge of the soldier, unless it were suspended by lust or avarice, was satiated by an undistinguishing massacre. The governor, who had yielded on a promise of mercy, was burned alive a few days afterwards, on a charge of having uttered some disrespectful words against the honour of Prince Hormisdas. The fortifications were razed to the ground; and not a vestige was left to indicate that the city of Maogamalcha had ever existed.
The successful valour of Julian had triumphed over all the obstacles that opposed his march to the gates of Ctesiphon. But the reduction, or even the siege, of the capital of Persia, was still at a distance; nor can the military conduct of the emperor be clearly apprehended, without a knowledge of the country which was the theatre of his bold and skilful operations. Twenty miles to the south of Baghdad, and on the eastern bank of the Tigris, the curiosity of travellers has observed some ruins of the palaces of Ctesiphon, which, in the time of Julian, was a great and populous city. The name and glory of the adjacent Seleucia were forever extinguished; and the only remaining quarter of that Greek colony had resumed, with the Assyrian language and manners, the primitive appellation of Coche.