=193.= Not content with her continental domains, Carthage gained possession of most of the islands of the western Mediterranean. The coast of Sicily was already dotted with Phœnician trading stations. These came under the control of Carthage; and though out-rivaled in prosperity by the free cities of the Greeks, especially Agrigen´tum and Syr´acuse, the western portion of the island long remained a valuable possession. The Balearic Islands were occupied by Carthaginian troops. Sardinia was conquered by a long and severe conflict, and became a most important station for the trade with Western Europe. Settlements were established in Corsica and Spain, while, in the Atlantic, the islands of Madeira and the Canaries were early subdued. =194.= These conquests were made chiefly by means of foreign mercenaries drawn both from Europe and Africa. South and west of Carthage were the barbarous but usually friendly tribes of Numid´ia and Mauritania; and her merchants in their journeys had frequent dealings with the warlike races of Spain, Gaul, and northern Italy. It is said that the Carthaginians mingled these various nations in their armies in such a manner that difference of language might prevent their plotting together. =195.= The navy of Carthage was of great importance in protecting her commerce from the swarms of pirates which infested the Mediterranean. The galleys were propelled by oars in the hands of slaves, but the officers and sailors were usually native Carthaginians. With these land and naval forces, Carthage became for several centuries undisputed mistress of the central and western Mediterranean. [Sidenote: B. C. 509.] =196.= Toward the middle of the sixth century B. C., a great commercial rival appeared in the western waters. The Greeks had begun their system of colonization; had opened a trade with Tartes´sus, multiplied their settlements in Sicily and Corsica, and built Massil´ia near the mouth of the Rhone. Near the close of our First Period, the two powers came into fierce collision, and the Grecian fleet was destroyed by that of Carthage, aided by her Etruscan allies. At the same time Rome, which had grown powerful under her kings, became free by their expulsion; and the Carthaginians, hitherto on friendly terms with the Italians, made a treaty of alliance with the new Republic which was to prove their most unrelenting foe. =197.= The government of Carthage, under the forms of a republic, was really an aristocracy of wealth. The two chief officers were the Suffe´tes, who at first, like the Hebrew rulers from Joshua to Samuel, led the people in war and judged them in peace. In later times their office became exclusively civil, and generals were appointed for military command. The Suffetes were elected only from certain families, and probably for life.