. Western Mesopotamia, or the tract
between the Euphrates and the Khabour, passed under the dominion of Rome
at this time; and, though not reduced to the condition of a province,
was none the less lost to Parthia, and absorbed by Rome into her
territory. Parthia, moreover, was penetrated by the Roman arms more
deeply at this time than she had ever been previously, and was made to
feel, as she had never felt before, that in contending with Rome she was
fighting a losing battle. It added to the disgrace of her defeats, and
to her own sense of their decisive character, that they were inflicted
by a mere general, a man of no very great eminence, and one who was far
from possessing the free command of those immense resources which Rome
had at her disposal.

Parthia had now, in fact, entered upon the third stage of her decline.
The first was reached when she ceased to be an aggressive and was
content to become a stationary power; the second set in when she began
to lose territory by the revolt of her own subjects; the third--which
commences at this point--is marked by her inability to protect herself
from the attacks of a foreign assailant. The causes of her decline were
various. Luxury had no doubt done its ordinary work upon the conquerors
of rich and highly-civilized regions, softening down their original
ferocity, and rendering them at once less robust in frame and less bold
and venturesome in character.

The natural law of exhaustion, which sooner or later affects all
races of any distinction, may also not improbably have come into play,
rendering the Parthians of the age of Verus very degenerate descendants
of those who displayed such brilliant qualities when they contended with
Crassus and Mark Antony. Loyalty towards the monarch, and the absolute
devotion of every energy to his service, which characterized, the
earlier times, dwindled and disappeared as the succession became
more and more disputed, and the kings less worthy of their subjects'
admiration. The strength needed against foreign enemies was, moreover,
frequently expended in civil broils; the spirit of patriotism declined;
and tameness under insult and indignity took the place of that fierce
pride and fiery self-assertion which had once characterized the people.

The war with Rome terminated in the year A.D. 165. Volagases survived
its close for at least twenty-five years; but he did not venture at any
time to renew the struggle, or to make any effort for