Skyros was previously called Pelasgia or Dolopia or Isle of magnets and was originally inhabited by Carians and Pelasgians Dolopes. The current name is attributed to either the Phoenicians or the word skirron (= plaster). The island is connected with Achilles which his mother Thetis had hidden there, in the Court of King Licomedes, in order not to participate in the Trojan War. King Lycomedes was also the one who killed Theseus precipitating him from the rocks of Skyros into the sea.
When in 470 BC Cimon conquered Skyros, moved from the island the bones of the national hero of Athens back to Athens and settled in Skyros Athenian colonists. Since then and until almost the end of antiquity Skyros was a satellite of Athens.
From archaeological findings it appears that the island was inhabited continuously from the Late Neolithic times. Remains of classic fortifications of the city have been incorporated in the Venetian castle of the homonymous capital city of the island.