Themistocles said the wooden walls meant the ships, and that the Athenians were all to sail away and leave the city.  Others would have it that the wooden walls were the old thorn fence of the Acropolis, and these, being mostly old people, chose to stay, while all the rest went away; and while the wives and children were kindly sheltered by their friends in the Peloponnesus, the men all joined the fleet, which lay off Salamis, and was now 366 in number.  The Persians overran the whole country, overcame the few who held out the Acropolis, and set Athens on fire.  All the hope of Greece was now in the fleet, which lay in the strait between Attica and the isle of Salamis.  Eurybiades, the Spartan commander, still wanted not to fight, but Themistocles was resolved on the battle.  Eurybiades did all he could to silence him.  “Those who begin a race before the signal are scourged,” said the Spartan.  “True,” said Themistocles; “but the laggards never win a crown.”  Eurybiades raised his leading staff as if to give him a blow.  “Strike, but hear me,” said Themistocles; and then he showed such good reason for there meeting the battle that Eurybiades gave way.  Six days later the Persian fleet, in all its grandeur, came up, and Xerxes caused his throne to be set on Mount Ægaleos, above the strait, that he might see the battle. The doubts of the Peloponnesians revived.  They wanted to sail away and guard their own shores, but Themistocles was so resolved that they should fight that he sent a slave with a message to Xerxes, pretending to be a traitor, and advising him to send ships to stop up the other end of the strait, to cut off their retreat.  This was done, to the horror of honest Aristides, who, still exiled, was in Ægina, watching what to do for his countrymen.  In a little boat he made his way at night to the ship where council was being held, and begged that Themistocles might be called out. “Let us be rivals still,” he said; “but let our strife be which can serve our country best.  I come to say that your retreat is cut off.  We are surrounded, and must fight.”  Themistocles said it was the best thing that could happen, and led him into the council with his tidings.