Skyros (Greek: Σκύρος) is an island in Greece the southernmost of the Sporades, an archipelago in the Aegean Sea. Around the 2nd millennium BC and slightly later, the island was known as The Island of the Magnetes where the Magnetes used to live and later Pelasgia and Dolopia and later Skyros. At 209 square kilometres (81 sq mi) it is the largest of the Sporades, and has a population of about 3,000 (in 2011). It is part of the regional unit of Euboea.
According to Greek mythology, Theseus died on Skyros when he was thrown from a cliff. Neoptolemus, son of Achilles, was from Skyros (or Scyros, as its name is sometimes transliterated), as told in the play by Sophocles, Philoctetes (line 239). In c. 475 BC, according to Thucydides, Cimon defeated the Dolopians (the original inhabitants) and conquered the entire island. From that date, it was colonized by Athenian settlers and became a part of the Athenian Empire. It was on the strategic trade route from Athens to the Black Sea. Cimon claimed to have found the remains of Theseus, and returned them to Athens.