IOLCUS(Ἰωλκός, Ep. Ἰαωλκός, Dor. Ἰαλκός: Eth. Ἰώλκιος, fem. Ἰωλκίς, Ἰωλκίας), an ancient city of Magnesia in Thessaly, situated at the head of the Pagasaean gulf and at the foot of Mt. Pelion (Pind. N. 4.88), and celebrated in the heroic ages as the residence of Jason, and the place where the Argonauts assembled. [See Dict. of Biogr. artt. JASON and ARGONAUTAE.] It is mentioned by Homer, who gives it the epithets of ἐϋκτιμένηand εὐρύχορος (II. 2.712, Od. 11.256). It is said to have been founded by Cretheus (Apollod. 1.9.11), and to have been colonised by Minyans from Orchomenos. (Strab. 9. p. 414.) lolcus is rarely mentioned in historical times. It was given by the Thessalians to Hippias, upon his expulsion from Athens. (Hdt. 5.94.) The town afterwards suffered from the dissensions of its inhabitants, but it was finally ruined by the foundation of Demetrias in B.C. 290, when the inhabitants of Iolcos and of other adjoining towns were removed to this place. (Strab. 9. p. 436.) It seems to have been no longer in existence in the time of Strabo, since he speaks of the place where Iolcos stood (ὁ τῆς Ἰωλκοῦ τόπος, 9. p. 438).
The position of Iolcos is indicated by Strabo, who says that it was on the road from Boebe to Denietrias, and at the distance of 7 stadia from the latter (9. p. 438). In another passage he says that lolcos is situated above the sea at the distance of 7 stadia from Demetrias (9. p. 436). Pindar also, as we have already seen, places Iolcos at the foot of Mt. Pelion, consequently a little inland. From these descriptions there is little doubt that Leake is right in placing Iolcos on the steep height between the southernmost houses of Voloand Vlckho-makhalá, upon which stands a church called Episkopí. There are at present no ancient remains at this place; but some large squared blocks of stone are said to have formerly existed at the foot of the height, and to have been carried away for the construction of buildings elsewhere. Moreover, it is the only spot in the neighbourhood which has any appearance of being an ancient site. It might indeed appear, from Livy (Liv. 44.12, 13), that lolcus was situated upon the coast; but in this passage, as well as in Strabo (9. p. 436), the name of lolcos seems to have been given to this part of the coast as well as to the city itself. (Leake, Northern Greece, vol. 4. p. 379; Mézieres, Mémoire sur le Pelion et l'Ossa, p. 11.)