Themistocles was probably the most brilliant and shrewd leader that Athens had in the fifth century BC. He had a good understanding of not just the Greek society but also the Persian Empire. He fought the Persians, but he had a good relationship with them.
When the Emperors of Persia, Darius I and his son Xerxes, attacked Greece, between 490 BC and 480 BC, the Athenians and Spartans were forced to ally to prevent the Persians from conquering their homeland. Themistocles was made the commander of the Greek allied navy in 480 BC. He used subterfuge to lure the Persian fleet into the Straits of Salamis, where they were defeated (Battle of Salamis).
Within a few years of the war against the Persians, there was a decline in Themistocles’s political fortunes. In 471 BC, the Athenian assembly, acting under Spartan pressure, ostracized him and exiled him to Argos. The Spartans despised Themistocles because he had ordered the re-fortification of Athens. When the Spartans implicated Themistocles in a treasonous plot against their general and tried to have him executed in Argos, he fled from Greece.
For some time Themistocles lived at Pydna under the protection of King Alexander I of Macedon. Eventually he travelled to Asia Minor, which was the territory of the Persian Empire, whose navy he had defeated in 480 BC. The son of Xerxes, Artaxerxes I, was reigning when Themistocles arrived.
In a year, Themistocles learned the Persian language and wrote a letter to Emperor Artaxerxes I. According to the account given by Thucydides, in his letter, Themistocles introduced himself to Artaxerxes I with these words:
"I, Themistocles, am come to you, who did your house more harm than any of the Hellenes, when I was compelled to defend myself against your father's invasion—harm, however, far surpassed by the good that I did him during his retreat, which brought no danger for me but much for him.”
Artaxerxes I was pleased that such an illustrious and dangerous foe had come to his empire and was ready to serve him. He made Themistocles the governor of Magnesia, where Themistocles lived for the rest of his life. With the help of some friends, the wife and children of Themistocles managed to escape from Athens and join him in Magnesia.
Themistocles died from natural causes in 459 BC, but several generations of his descendants continued to live under the protection of the Persian Emperor, and serve as the governor of Magnesia.