retreated
even designedly, and, when they had drawn off our men a short distance
from the legions, leaped from their chariots and fought on foot in
unequal [and to them advantageous] battle. But the system of cavalry
engagement is wont to produce equal danger, and indeed the same, both to
those who retreat and those who pursue. To this was added, that they
never fought in close order, but in small parties and at great
distances, and had detachments placed [in different parts], and then the
one relieved the other, and the vigorous and fresh succeeded the
wearied.

XVII.--The following day the enemy halted on the hills, a distance from
our camp, and presented themselves in small parties, and began to
challenge our horse to battle with less spirit than the day before. But
at noon, when Caesar had sent three legions, and all the cavalry with C.
Trebonius, the lieutenant, for the purpose of foraging, they flew upon
the foragers suddenly from all quarters, so that they did not keep off
[even] from the standards and the legions. Our men making an attack on
them vigorously, repulsed them; nor did they cease to pursue them until
the horse, relying on relief, as they saw the legions behind them, drove
the enemy precipitately before them, and, slaying a great number of
them, did not give them the opportunity either of rallying or halting,
or leaping from their chariots. Immediately after this retreat, the
auxiliaries who had assembled from all sides, departed; nor after that
time did the enemy ever engage with us in very large numbers.

XVIII.--Caesar, discovering their design, leads his army into the
territories of Cassivellaunus to the river Thames; which river can be
forded in one place only, and that with difficulty. When he had arrived
there, he perceives that numerous forces of the enemy were marshalled on
the other bank of the river; the bank also was defended by sharp stakes
fixed in front, and stakes of the same kind fixed under the water were
covered by the river. These things being discovered from [some]
prisoners and deserters, Caesar, sending forward the cavalry, ordered
the legions to follow them immediately. But the soldiers advanced with
such speed and such ardour, though they stood above the water by their
heads only, that the enemy could not sustain the attack of the legions
and of the horse, and quitted the banks, and committed themselves to
flight.

XIX.--Cassivellaunus, as we have stated above, all hope [ri