When the Persian army had been again defeated at Plataea and Mycale in B.C. 479, and when the Athenians had rebuilt their private dwellings, it was also resolved, on the advice of Themistocles, to restore the fortifications of Athens, but on a larger scale than they had been before, and more in accordance with the proud position which the city now occupied in Greece. This plan excited the fear and jealousy of the rival states, and especially of Sparta, which sent an embassy to Athens, and under the veil of friendship, which ill concealed its selfish policy, endeavored to persuade the Athenians not to fortify the city. Themistocles, who saw through their designs, undertook the task of defeating them with their own weapons. He advised his countrymen to dismiss the Spartan ambassadors, and to promise that Athenian envoys should be sent to Sparta to treat with them there respecting the fortifications. He himself offered to go as one of the envoys, but he directed the Athenians not to let his colleagues follow him until the walls, on which all hands should be employed during his absence, should be raised to such a height as to afford sufficient protection against any attack that might be made upon them. His advice was followed, and Themistocles, after his arrival at Sparta, took no steps toward opening the negotiations, but pretended that he was obliged to wait for the arrival of his colleagues. When he was informed that the walls had reached a sufficient height, and when he could drop the mask with safety, he gave the Spartans a well-deserved rebuke, returned home, and the walls were completed without any hindrance. He then proceeded to carry into effect the chief thing which remained to be done to make Athens the first maritime power of Greece. He induced the Athenians to fortify the three ports of Phalerum, Munychia, and Piraeus by a double range of walls. [Illustration: The victors of Salamis.]