The campaigns of the Great Persian War have been described, once for all, in the glowing pages of the Greek historian, Herodotus. [6] Early in the year 480 B.C. the Persian host moved out of Sardis, crossed the Hellespont, and advanced to the pass of Thermopylae, commanding the entrance to central Greece. This position, one of great natural strength, was held by a few thousand Greeks under the Spartan king, Leonidas. For two days Xerxes hurled his best soldiers against the defenders of Thermopylae, only to find that numbers did not count in that narrow defile. There is no telling how long the handful of Greeks might have kept back the Persian hordes, had not treachery come to the aid of the enemy. A traitor Greek revealed to Xerxes the existence of an unfrequented path, leading over the mountain in the rear of the pass. A Persian detachment marched over the trail by night and took up a position behind the Greeks. The latter still had time to escape, but three hundred Spartans and perhaps two thousand allies refused to desert their post. While Persian officers provided with whips lashed their unwilling troops to battle, Leonidas and his men fought till spears and swords were broken, and hands and teeth alone remained as weapons. Xerxes at length gained the pass--but only over the bodies of its heroic defenders. Years later a monument to their memory was raised on the field of battle. It bore the simple inscription: "Stranger, go tell the Spartans that we lie here in obedience to their commands." [7] AFTER THERMOPYLAE After the disaster at Thermopylae nearly all the states of central Greece submitted to the Persians. They marched rapidly through Boeotia and Attica to Athens, but found a deserted city. Upon the advice of Themistocles the non-combatants had withdrawn to places of safety, and the entire fighting force of Athens had embarked on the ships. The Athenian fleet took up a position in the strait separating the island of Salamis from Attica and awaited the enemy. [8] BATTLE OF SALAMIS, 480 B.C. The battle of Salamis affords an interesting example of naval tactics in antiquity. The trireme was regarded as a missile to be hurled with sudden violence against the opposing ship, in order to disable or sink it. A sea fight became a series of maneuvers; and victory depended as much on the skill of the rowers and steersmen as on the bravery of the soldiers. The Persians at Salamis had many more ships than the Greeks, but Themistocles rightly believed that in the narrow strait their numbers would be a real disadvantage to them. Such proved to be the case. The Persians fought well, but their vessels, crowded together, could not navigate properly and even wrecked one another by collision. After an all-day contest what remained of their fleet withdrew from the strait.