But just as the East India Company found it necessary to conquer the neighbouring territory in order to secure peaceful trade, so Carthage extended its conquests all down the western coast of Africa and the south-east part of Spain, while Rome was extending into Italy.

To continue our conchological analogy, by the time of the first Punic War Rome and Carthage had each expanded into a shell, and between the two intervened the eastern section of the island of Sicily.

As the result of this, Rome became master of Sicily, and then the final struggle took place with Hannibal in the second Punic War, which resulted in Rome becoming possessed of Spain and Carthage.

By the year 200 B.C.Rome was practically master of the Western Mediterranean, though it took another century to consolidate its heritage from Carthage in Spain and Mauritania.
During that century--the second before our era--Rome also extended its Italian boundaries to the Alps by the conquest of Cisalpine Gaul, which, however, was considered outside Italy, from which it was separated by the river Rubicon.

In that same century the Romans had begun to interfere in the affairs of Greece, which easily fell into their hands, and thus prepared the way for their inheritance of Alexander's empire.
This, in the main, was the work of the first century before our era, when the expansion of Rome became practically concluded.