cavalry
to come to an engagement with them; and they found, even when they
did come to a hand-to-hand conflict, an equal if not superior
adversary in the iron-clad hosts of lancers. As compared with an
army like this Parthian one, the Roman army was at a disadvantage
strategically, because the cavalry commanded the communications;
and at a disadvantage tactically, because every weapon of close
combat must succumb to that which is wielded from a distance,
unless the struggle becomes an individual one, man against man.
The concentrated position, on which the whole Roman method of war
was based, increased the danger in presence of such an attack;
the closer the ranks of the Roman column, the more irresistible
certainly was its onset, but the less also could the missiles
fail to hit their mark. Under ordinary circumstances,
where towns have to be defended and difficulties of the ground
have to be considered, such tactics operating merely with cavalry
against infantry could never be completely carried out;
but in the Mesopotamian desert, where the army, almost like a ship
on the high seas, neither encountered an obstacle nor met
with a basis for strategic dispositions during many days' march,
this mode of warfare was irresistible for the very reason
that circumstances allowed it to be developed there in all its purity
and therefore in all its power. There everything combined to put
the foreign infantry at a disadvantage against the native cavalry.
Where the heavy-laden Roman foot-soldier dragged himself toilsomely
through the sand or the steppe, and perished from hunger or still more
from thirst amid the pathless route marked only by water-springs
that were far apart and difficult to find, the Parthian horseman,
accustomed from childhood to sit on his fleet steed or camel,
nay almost to spend his life in the saddle, easily traversed
the desert whose hardships he had long learned how to lighten
or in case of need to endure. There no rain fell to mitigate
the intolerable heat, and to slacken the bowstrings and leathern thongs
of the enemy's archers and slingers; there amidst the deep sand
at many places ordinary ditches and ramparts could hardly be formed
for the camp. Imagination can scarcely conceive a situation
in which all the military advantages were more on the one side,
and all the disadvantages more thoroughly on the other.

To the question, under what circumstances this new style
of tactics, the first nationa