all roads in history lead to Rome.

The work of Claudius Ptolemy sums up to us the knowledge that the
Romans had gained by their inheritance, on the western side, of
the Carthaginian empire, and, on the eastern, of the remains of
Alexander's empire, to which must be added the conquests of Cæsar
in North-West Europe. Cæsar is, indeed, the connecting link between
the two shells that had been growing throughout ancient history. He
added Gaul, Germany, and Britain to geographical knowledge, and,
by his struggle with Pompey, connected the Levant with his northerly
conquests. One result of his imperial work must be here referred
to. By bringing all civilised men under one rule, he prepared them
for the worship of one God. This was not without its influence on
travel and geographical discovery, for the great barrier between
mankind had always been the difference of religion, and Rome, by
breaking down the exclusiveness of local religions, and substituting
for them a general worship of the majesty of the Emperor, enabled
all the inhabitants of this vast empire to feel a certain communion
with one another, which ultimately, as we know, took on a religious
form.

The Roman Empire will henceforth form the centre from which to
regard any additions to geographical knowledge. As we shall see,
part of the knowledge acquired by the Romans was lost in the Dark
Ages succeeding the break-up of the empire; but for our purposes
this may be neglected and geographical discovery in the succeeding
chapters may be roughly taken to be additions and corrections of
the knowledge summed up by Claudius Ptolemy.