The following are the chief islands: - Thasos, in the extreme north, off the Macedonian coast; Samothrace, fronting the Gulf of Saros; Imbros and Lemnos, in prolongation of the peninsula of Gallipoli (Thracian Chersonese); Euboea, the largest of all, lying close along the east coast of Greece; the Northern Sporades, including Sciathos, Scopelos and Halonesos, running out from the southern extremity of the Thessalian coast, and Scyros, with its satellites, north-east of Euboea; Lesbos and Chios; Samos and Nikaria; Cos, with Calymnos to the north; all off Asia Minor, with the many other islands of the Sporades; and, finally, the great group of the Cyclades, of which the largest are Andros and Tenos, Naxos and Paros.
To these must be added the Turkish islands in the Aegean usually reckoned to Europe, that is, Thasos, Samothrace, Imbros and, in the extreme south, Crete or Candia.
The north-eastern portion of the Aegean, owing to its proximity to the coast of Thrace, was known as the Thracian Sea, and in this were situated the islands of Thasos, Samothrace and Imbros.
The result was that, in the cases of Naxos and Thasos, for instance, the league's resources were employed not against the Persians but against recalcitrant Greek islands, and that the Greek ideal of separate autonomy was outraged.
In 463 after a siege of more than two years the Athenians captured Thasos, with which they had quarrelled over mining rights in the Strymon valley.