One of the greatest statesmen Athens
ever produced (Thucydides
considered him greater than even Pericles
himself), and the person who has contributed more than any other to the rise of Athens
from a minor Greek polis
to one of the two most powerful poleis
He was born c. 524 BCE to a noble Athenian family, but from a foreign mother. He was elected Archon Eponymos in 493 BCE. He was the one that started building Athens as a maritime empire, and began the development of Piraeus as Athens' harbour.
He continued to be a prominent figure in the political life of Athens also after the end of his Archontate year, (after all he was only about 32), which can be easily seen by repeated attempts to deport him by Ostrakismos during the 480's. It is assumed that he was behind the Ostrakismoi that sent Xanthippus and Aristides into exile.
In 487 BCE, after the great silver mines in Laurion were discovered, he managed to pass a decision in the Ecclesia, directing any surplus in the profits from the mines into the building of the Athenian fleet. The ships were allegedly supposed to play a part in the war against Aegina, but Themistocles knew that they'd be the key element in making Athens a major competant in the fight for supremacy in Greece. And indeed the Athenian fleet played the decisive role in the Persian war of 480 BCE.
In this war Themistocles was appointed supreme commander of the Athenian forces within the united Greek army. When the Greek armies (lead by Sparta) were defeated in Boeotia and decided to build the second line of defense in the Isthmus, effectively abandoning Athens to the grace of the Persians (who 'had it in' for the Athenians anyway since the battle of Marathon), he organized the transfer of all Athenian citizens to Salamis (cf.), and tricked both the Persians and the other Greeks into engaging in battle in the waters of the straits of Salamis, before the Greeks actually built those second defense lines in the Isthmus. In this battle the Persian fleet was effectively crushed, and Themistocles became the hero of the day, saving Greece without sacrificing Athens.
After the war his policy of building Athens as a maritime empire finally got the credit it was due, and even his greatest opponent, Aristides, became his supporter.
However, the rise of Athens as a major player in Panhellenic politics, brought forth the hostility of Sparta, who was until then the unchallanged leader of Greece. As Aristides and Cimon worked on building the Delian League, Themistocles went to Sparta, in order to appease them, and make sure to them that the thing Sparta was most afraid of, Athens' building of the Long Walls, connecting the city of Athens with the harbour in Piraeus with one singular structure, would not happen. He managed to delay the Spartan for such an amount of time, that by the time the Spartans found out he was lying, the wall was already completed. Themistocles had to escape Sparta for fear of his life. In 470 BCE Themistocles' enemies finally won over and in one of the most famous Ostrakismoi ever, he was sent into exile. Pieces of clay that were found from this particular Ostrakismos show that some circles in town mass-produced hundreds of clay pieces with Themistocles' name on them.
Themistocles then went to live in Argos, Sparta's traditional enemy, and from there (ever loyal to his homeland) worked to weaken Sparta's clout on the Peloponnese, encouraging, aiding financially and even organizing anti-Spartan movements throughout the peninsula.
When Sparta became alarmed, allegations were made that she had evidence that he was collaborating with Pausanias (a Spartan renegade king, that due to his behaviour was accused of treason against Greece in various poleis throughout Greece), and Themistocles had to flee to Asia Minor. The Athenians, not wanting to antagonize Sparta too much as of yet, condemned him to death in absentia.
Artaxerxes II of Persia appointed him governor of Magnesia in 465 BCE where he died in 459.
However, his loyalty to Athens never ceased, and in the end of the 460's he was involved in the rise to power of democratic, anti-Spartan leadership.