been judiciously constructed,
and should perhaps be ascribed rather to the friends whom the youthful
emperor consulted than to his own unassisted wisdom. But the best
designed plans may be frustrated by unskilfulness or timidity in the
execution; and it was here, if we may trust the author who alone
gives us any detailed account of the campaign, that the weakness of
Alexander's character showed itself. The northern army successfully
traversed Armenia, and, invading Media, proved itself in numerous small
actions superior to the Persian force opposed to it, and was able to
plunder and ravage the entire country at its pleasure. The southern
division crossed Mesopotamia in safety, and threatened to invade Persia
Proper. Had Alexander with the third and main division kept faith
with the two secondary armies, had he marched briskly and combined his
movements with theirs, the triumph of the Roman arms would have been
assured. But, either from personal timidity or from an amiable regard
for the anxieties of his mother Mamsea, he hung back while his right and
left wings made their advance, and so allowed the enemy to concentrate
their efforts on these two isolated bodies. The army in Media, favored
by the rugged character of the country, was able to maintain its ground
without much difficulty; but that which had advanced by the line of the
Euphrates and Tigris, and which was still marching through the boundless
plains of the great alluvium, found itself suddenly beset by a countless
host, commanded by Artaxerxes in person, and, though it struggled
gallantly, was overwhelmed and utterly destroyed by the arrows of the
terrible Persian bowmen. Herodian says, no doubt with some exaggeration,
that this was the greatest calamity which had ever befallen the Romans.
It certainly cannot compare with Cannae, with the disaster of Varus, or
even with the similar defeat of Crassus in a not very distant region.
But it was (if rightly represented by Herodian) a terrible blow. It
absolutely determined the campaign. A Caesar or a Trajan might have
retrieved such a loss. An Alexander Severus was not likely even to make
an attempt to do so. Already weakened in body by the heat of the climate
and the unwonted fatigues of war, he was utterly prostrated in spirit by
the intelligence when it reached him. The signal was at once given for
retreat. Orders were sent to the _corps d' armee_ which occupied Media
to evacuate its conquests and to retire forthw