Only the Grecian fleet remained. It was vastly out-numbered by the Persian fleet. But it was manned by patriots trained to fight on the water; while the Persians themselves were nearly all landsmen, and so had to depend on the Phoenicians and colonial Greek seamen, who were none too eager for the fray. Seeing the Persians too densely massed together on a narrow front the Greek commander, Themistocles, attacked with equal skill and fury, rolled up the Persian front in confusion on the mass behind, and won the battle that saved the Western World. The Persians lost two hundred vessels against only forty Greek. But it was not the mere loss of vessels, or even of this battle of Salamis itself, that forced Xerxes to give up all hopes of conquest. The real reason was his having lost the command of the sea. He knew that the victorious Greeks could now beat the fighting ships escorting his supply vessels coming overseas from Asia Minor, and that, without the constant supplies of men, arms, food, and everything else an army needs, his army itself must wither away. Two hundred and twenty years later the sea-power of the Roman West beat both the land- and sea-power of the Carthaginian East; and for the very same reason. Carthage was an independent colony of Phoenicians which had won an empire in the western Mediterranean by its sea-power. It held a great part of Spain, the whole of Sardinia, most of Sicily, and many other islands. The Romans saw that they would never be safe as long as Carthage had the stronger navy; so they began to build one of their own. They copied a Carthaginian war galley that had been wrecked; and meanwhile taught their men to row on benches set up ashore. This made the Carthaginians laugh and led them to expect an easy victory. But the Romans were thorough in everything they did, and they had the best trained soldiers in the world. They knew the Carthaginians could handle war galleys better than they could themselves; so they tried to give their soldiers the best possible chance when once the galleys closed. They made a sort of drawbridge that could be let down with a bang on the enemy boats and there held fast by sharp iron spikes biting into the enemy decks. Then their soldiers charged across and cleared everything before them. [Illustration: ROMAN TRIREME--A vessel with three benches of oars]