Themistocles (ca. 525 BC-460 BC) was a leader in the Athenian democracy during the Persian War. Themistocles favored the expansion of the navy to meet the Persian threat and persuaded the Athenians to spend the surplus generated by their silver mines on building new ships - the Athenian navy grew from 70 to 200 ships.
He was the son of Neocles, an Athenian of no distinction and moderate means, his mother being a Carian or a Thracian. Hence according to the Periclean law, which of course came several decades later, he would not have been a free Athenian at all. Thucydides properly brings out the fact that, though he lacked education, he displayed a marvellous power of analysing a complex situation together with a genius for rapid action. Plutarch similarly enlarges on his consuming ambition for power both personal and national, and the unscrupulous ability with which he pursued his ends. In all these points he is the antithesis of his rival Aristides. Little is known of his early years. He may have been strategos of his tribe at Marathon and we are told that he deeply envied the glory which Miltiades earned. This is attested by a phrase he is said of often repeating to himself "Miltiades' trophy does not let me sleep" (in Greek: "Ουκ εά με καθεύδειν το του Μιλτιάδου τρόπαιον").
At all events the death of Miltiades left the stage to Aristides and Themistocles. It is sufficiently clear that their rivalry, terminated in 483-82 by the ostracism of Aristides, turned largely on the fact that Themistocles was the advocate of a policy of naval expansion. This policy was unquestionably of the highest importance to Athens and indeed to Greece. Athens was faced by the equal if not superior power of Aegina, while the danger of a renewed Persian invasion loomed large on the horizon. Themistocles therefore persuaded his countrymen to build 200 triremes, and—what was of even greater importance—to fortify the three natural harbours of Piraeus in place of the open roadstead of Phalerum. For the building of the ships Themistocles persuaded the Athenians to allocate 100 talents (around $60,000,000) obtained from the new silver mines at Laurium which were about to be distributed to the citizens. One hundred of the proposed 200 were built.
Themistocles may have been archon in 483-82 at the time when this naval programme began. Dionysius of Halicarnassus places his archonship in 493-92, in favour of which are several considerations. In 487 the office lost much of its importance owing to the substitution of the lot for election: the chance that the lot would at the particular crisis of 483 fall on Themistocles was obviously remote. In any case the year prior to the invasion of Xerxes found Themistocles the most influential politician in Athens if not in Greece. Though the Greek fleet was nominally under the control of the Spartan Eurybiades, it was Themistocles who caused the Greeks to fight the indecisive Battle of Artemisium, and still more it was he who, by his threat that he would lead the Athenian army to found a new home in the West, and by his seemingly treacherous message to Xerxes, brought about the Battle of Salamis.
The retirement of the Persians left the Athenians free to restore their ruined city. Sparta, nominally on the ground that it was dangerous to Greece that there should be any citadel north of the Isthmus of Corinth which an invader might hold, urged that this should not be done, but Themistocles by means of diplomatic delays and subterfuges enabled the work to be carried sufficiently near to completion to make the walls defensible. He also carried out his original plan of making Piraeus a real harbour and fortress for Athens. Athens thus became the finest trade centre in Greece, and this fact, coupled with Themistocles’ remission of the alien’s tax, induced many foreign business men to settle in Athens.
After the crisis of the Persian invasion Themistocles and Aristides appear to have made up their differences. But Themistocles soon began to lose the confidence of the people, partly owing to his arrogance (it is said that he built near his own house a sanctuary to Artemis Aristoboulë “of good counsel “) and partly to his alleged readiness to take bribes. Diodorus and Plutarch both refer to some accusation levelled against him, and some time between 476 and 471 he was ostracized. He retired to Argos, but the Spartans further accused him of treasonable intrigues with Persia, and he fled to Corcyra, thence to Admetus, king of Molossia, and finally to Asia Minor. He was proclaimed a traitor at Athens and his property was confiscated, though his friends saved him some portion of it.
He was well received by the Persians and was allowed to settle in Magnesia on the Maeander River. The revenues (50 talents) of this town were assigned to him for bread, those of Myus for condiments, those of Lampsacus for wine. His death, at the age of sixty five, at Magnesia, was possibly due to illness - although Thucydides (book I, 138) tells us that he possibly committed suicide by taking poison, when he found that he could not keep the promises that he had made to Xerxes. It was said that his bones were secretly transferred to Attica. He was worshipped by the Magnesians as a god, as we find from a coin on which he is shown with a patera in his hand and a slain bull at his feet (hence perhaps the legend that he died from drinking bull’s blood).
Though his end was discreditable, though his great wealth can hardly have been obtained by loyal public service, there is no doubt that his services to Athens and to Greece were great. He created the Athenian fleet and with it the possibility of the Delian League which became the Athenian empire, and there are many indications (e.g. his well-attested plan of expansion in the west) that the later imperialist ideal originated with him.