Owing to them, in a large measure, Rome was enabled to preserve its empire intact for nearly five hundred years, and even to this day one can trace a difference in the civilisation of those countries over which Rome once ruled, except where the devastating influence of Islam has passed like a sponge over the old Roman provinces.

Civilisation, or the art of living together in society, is practically the result of Roman law, and this sense 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 Caesar in North-West Europe.

Caesar 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.