ailed him as to the practicability of the
undertaking. It can scarcely be supposed that the city was really
stronger now than it had been under the Parthians; much less can it be
argued that Julian's army was insufficient for the investment of such a
place. It was probably the most powerful army with which the Romans had
as yet invaded Southern Mesopotamia; and it was amply provided with
all the appurtenances of war. If Julian did not venture to attempt what
Trajan and Avidius Cassius and Septimius Severus had achieved without
difficulty, it must have been because the circumstances under which he
would have had to make the attack were different from those under which
they had ventured and succeeded. And the difference--a most momentous
one--was this. They besieged and captured the place after defeating the
greatest force that Parthia could bring into the field against them.
Julian found himself in front of Ctesiphon before he had crossed swords
with the Persian king, or so much as set eyes on the grand army which
Sapor was known to have collected. To have sat down before Ctesiphon
under such circumstances would have been to expose himself to great
peril; while he was intent upon the siege, he might at any time have
been attacked by a relieving army under the Great King, have been placed
between two fires, and compelled to engage at extreme disadvantage. It
was a consideration of this danger that impelled the council of war,
whereto he submitted the question, to pronounce the siege of Ctesiphon
too hazardous an operation, and to dissuade the emperor from attempting
it.

But, if the city were not to be besieged, what course could with any
prudence be adopted? It would have been madness to leave Ctesiphon
unassailed, and to press forward against Susa and Persepolis. It would
have been futile to remain encamped before the walls without commencing
a siege. The heats of summer had arrived, and the malaria of autumn was
not far off. The stores brought by the fleet were exhausted; and there
was a great risk in the army's depending wholly for its subsistence on
the supplies that it might be able to obtain from the enemy's country.
Julian and his advisers must have seen at a glance that if the Romans
were not to attack Ctesiphon, they must retreat. And accordingly retreat
seems to have been at once determined on. As a first step, the whole
fleet, except some dozen vessels, was burned, since twelve was a
sufficient number to serve