[Sidenote: The domestic necessity for foreign war.] In these domestic disputes we see the origin of the Roman necessity for war. The high caste is steadily diminishing in number, the low caste as steadily increasing. In imperious pride, the patrician fills his private jail with debtors and delinquents; he usurps the lands that have been conquered. Insurrection is the inevitable consequence, foreign war the only relief. As the circle of operations extends, both parties see their interest in a cordial coalescence on equal terms, and jointly tyrannize exteriorly. [Sidenote: Gradual spread of Roman influence to the south.] [Sidenote: Rome builds a navy,] [Sidenote: and invades Africa.] [Sidenote: Results of the first Punic War.] [Sidenote: Results of the second Punic War.] [Sidenote: Rome invades Greece,] [Sidenote: and compels the cession of all the European provinces of Antiochus.] [Sidenote: Revolt of Perses.] [Sidenote: Dreadful social effects on Rome.] [Sidenote: Plunder of Greece and annexation of Spain.] [Sidenote: Seizure of Asia Minor.] [Sidenote: The Servile and Social wars.] [Sidenote: Gradual convergence of power.] [Sidenote: Cæsar the master of the world.] The geographical dominion of Rome was extended at first with infinite difficulty. Up to the time of the capture of the city by the Gauls a doubtful existence was maintained in perpetual struggles with the adjacent towns and chieftains. There is reason to believe that in the very infancy of the republic, in the contest that ensued upon the expulsion of the kings, the city was taken by Porsenna. The direction in which her influence first spread was toward the south of the peninsula. Tarentum, one of the southern states, brought over to its assistance Pyrrhus the Epirot. He did little in the way of assisting his allies--he only saw Rome from the Acropolis of Præneste; but from him the Romans learned the art of fortifying camps, and caught the idea of invading Sicily. Here the rising republic came in contact with the Carthaginians, and in the conflict that ensued discovered the military value of Spain and Gaul, from which the Carthaginians drew an immense supply of mercenaries and munitions of war. The advance to greatness which Rome now made was prodigious. She saw that everything turned on the possession of the sea, and with admirable energy built a navy. In this her expectations were more than realized. The assertion is quite true that she spent more time in acquiring a little earth in Italy than was necessary for subduing the world after she had once obtained possession of the Mediterranean. From the experience of Agathocles she learned that the true method of controlling Carthage was by invading Africa. The principles involved in the contest, and the position of Rome at its close, are shown by the terms of the treaty of the first Punic War--that Carthage should evacuate every island in the Mediterranean, and pay a war-fine of six hundred thousand pounds.