Thasos, an island in the north of the Aegean Sea, off the coast of Thrace and the plain of the river Nestus (now the KaraSu). The island was colonized at an early date by Phoenicians, attracted probably by its gold mines; they founded a temple of Heracles, which still existed in the time of Herodotus. Thasus, son of Phoenix, is said to have been the leader of the Phoenicians, and to have given his name to the island. In 720 or 708 B.C. Thasos received a Greek colony from Paros. In a war which the Parian colonists waged with the Saians, a Thracian tribe, the poet Archilochus threw away his shield. The Greeks extended their power to the mainland, where they owned gold mines which were even more valuable than those on the island. From these sources the Thasians drew ,great wealth, their annual revenues amounting to 200 or even 300 talents. Herodotus, who visited Thasos, says that the best mines on the island were those which had been opened by the Phoenicians on the east side of the island facing Samothrace. The place was important during the Ionian revolt against Persia. After the capture of Miletus (494 B.C.) Histiaeus, the Ionian leader, laid siege to Thasos. The attack failed, but, warned by the danger, the Thasians employed their revenues to build war ships and strengthen their fortifications. This excited the suspicions of the Persians, and Darius compelled them to surrender their ships and pull down their walls. After the defeat of Xerxes the Thasians joined the Delian confederacy; but afterwards, on account of a difference about the mines and marts on the mainland, they revolted. The Athenians defeated them by sea, and, after a siege that lasted more than two years, took the capital, Thasos, probably in 463, and compelled the Thasians to destroy their walls, surrender their ships, pay an indemnity and an annual contribution (in 449 this was 21 talents, from 445 about 30 talents), and resign their possessions on the mainland. In 411 B.C., at the time of the oligarchical revolution at Athens, Thasos again revolted from Athens and received a Lacedaemonian governor; but in 407 the partisans of Lacedaelnon were expelled, and the Athenians under Thrasybulus were admitted. After the battle of Aegospotami (405 B.C.), Thasos again fell into the hands of the Lacedaemonians under Lysander who formed a decarchy there; but the Athenians must have recovered it, for it formed one of the subjects of dispute between them and Philip II. of Macedonia. In the embroilment between Philip III. of Macedonia and the Romans, Thasos submitted to Philip, but received its freedom at the hands of the Romans after the battle of Cynoscephalae (197 B.C.), and it was still a "free" state in the time of Pliny. After a period of Latin occupation, it was captured by the Turks in 1462; it was given by the Sultan Mahmud II. to Mehemet Ali of Egypt, and still remains the property of the khedive. Thasos, the capital, stood on the north side of the island, and had two harbours, one of which was closed. Archilochus described Thasos as "an ass's backbone crowned with wild wood," and the description still suits the mountainous island with its forests of fir. The highest mountain, Ipsario, is 3428 ft. high. Besides its gold mines, the wine, nuts and marble of Thasos were well known in antiquity. The mines and marble quarries are no longer worked; and the chief exports are now fir timber for shipbuilding, olive oil, honey and wax. The imports consist of manufactured goods, beasts of burden and corn, for the island is too mountainous to grow enough corn for the inhabitants.
The population, distributed in ten villages, is estimated at 8000. The people are Greek Christians, and do not differ in appearance from the inhabitants of the other Greek islands. The villages are mostly situated at some distance from the sea; for the island suffered from pirates. Even in the early part of the 19th century sentinels stood on duty night and day, and at a signal of alarm the whole population, including the Turkish aga himself, used to hide in the woods.
For a description of the island and its remains of antiquity, see A. Conze, Reise auf den Inseln des thrakischen Meeres (Hanover, 1860); for inscriptions see Inscr. Gr. xii. 8; the island is fully described by J. ff. Baker-Penoyre in Journal Hell. Stud. xxix. (1909).