As a warning against future
invasion, Caesar bridged the Rhine and made a demonstration upon the right
bank, destroying his bridge when he withdrew. Towards the close of the
summer he crossed the Straits of Dover to Britain, to punish the Britons
for aiding his enemies in Gaul. But owing to the lateness of the season
and the smallness of his force he returned to Gaul after a brief
reconnaissance.

In the following year, after gathering a larger fleet, he again landed on
the island with a force of almost 30,000 men. This time he forced his way
across the Thames and received the submission of Cassivellaunus, the chief
who led the British tribes against the invaders. After taking hostages,
and receiving promises of tribute, Caesar returned to Gaul. Britain was in
no sense subdued, but the island had felt the power of Rome, and, besides
enlarging the geographical knowledge of the time, Caesar had brought back
numbers of captives. In Rome the exploit produced great excitement and
enthusiasm.

*Revolts in Gaul: 54-53 B. C.* Although the Gauls had submitted to Caesar,
they were not yet reconciled to Roman rule, which put an end to their
inter-tribal wars and to the feuds among the nobility. Consequently, many
of the tribes were restive and not inclined to surrender all hopes of
freedom without another struggle. In the course of the winter 54-53 B. C.
the Nervii, Treveri and Eburones in Belgian Gaul attacked the Roman
detachments stationed in their territories. One of these was cut to pieces
but the rest held their ground until relieved by Caesar, who stamped out
the rebellion.

*Vercingetorix, 52 B. C.* A more serious movement started in 52 B. C.
among the peoples of central Gaul who found a national leader in
Vercingetorix, a young noble of the Arverni. The revolt took Caesar by
surprise when he was in Cisalpine Gaul and his troops still scattered in
winter quarters. He recrossed the Alps with all haste, secured the
Narbonese province and succeeded in uniting his forces. These he
strengthened with German cavalry from across the Rhine. However, a
temporary check in an attack upon the position of Vercingetorix at
Gergovia caused the Aedui to desert the Roman cause, and the revolt spread
to practically the whole of Gaul. Caesar was on the point of retiring to
the province, but after repulsing an attack made upon him he was able to
pen up Vercingetorix in the fortress of Alesia. A great effort made by the
Gauls to relieve the