Son of Militades and the daughter of the king of Thrace, Kymon was acclaimed both as a politician and general, rising to the latter post two years after the crucial naval battle at Salamis, which marked the ousting of the Persians from Greece, and in which he had distinguished himself for his bravery. Plutarch made the point that Kymon was victorious even after his demise. He was buried with great honors.
Kymon was orphaned at a young age and did not have a very good education, but played the lyre, was interested in poetry, and knew how to ride. After the Battle of Salamis he took up the reins of the conservative faction, this upon Aristides' death. From 476 to 463 BC he led the forces of the Delian League, and in 475 BC conquered the island of Skyros, ridding it of pirates, and returned to Athens with what were purported to be the bones of the great Athenian hero, Theseus, believed to have been buried on that island.
As a military leader he annexed the Thracian city of Eiona, which had a large Persian garrison, conquered Karystos (on the island of Evia.Euboea) and Naxos. In 466 BC he mounted a surprise attack against the Persians, who had gathered a naval and land force at the mouth of the Eurymedom River, and destroyed or captured 200 or the 350 ships assembled there. This was his greatest military achievement, though he suffered the fate of many great leaders, and was exiled for five years (to Voitia or Boetia, just north of Athens) after being accused of anti-democratic behavior, though Perikles summoned him back, despite being in the opposing political camp, this due to Kymon's obvious patriotism and laudable actions.
In 449 BC he became ill just after a defeat of the Persians off of Cyprus, a event in which he had headed a 200 ship fleet. As the fleet was returning to Athens it encountered a mixed Phonenician - Cilician fleet, allies of the Persians. Unaware that Kymon had died, the leaders were fearful that he was aboard the Hellenic fleet, and were easily routed.