The ancient city of Demetrias was founded in the early 3rd century BC by Demetrius Poliorcetes, in a strategic location on the Pagasetic Gulf, with the aim of creating a powerful Hellenistic center. The new city resulted from the synoecism of smaller settlements and the incorporation of the older city of Pagasae, quickly gaining political and economic importance.
The region, however, already had a long history of habitation dating back to the Neolithic period. At Pefkakia, significant prehistoric finds have been discovered, indicating continuous occupation from the Neolithic to the Bronze Age, with strong maritime and commercial activity and possible connections to Iolcos and the Argonautic tradition.
During the Hellenistic period, Demetrias developed into a major administrative and commercial port of the Antigonid dynasty, with a cosmopolitan character and strong strategic importance. After the Roman conquest, the city gradually declined, without completely losing its role as a local center until the Early Christian period, when it was finally abandoned in the 6th century AD.
Excavations have brought to light extensive parts of the fortifications, public buildings, the palace, the theatre, sanctuaries, residential complexes, and cemeteries, revealing the urban organization and diachronic development of one of the most important cities of ancient Thessaly.

http://odysseus.culture.gr/Συντάκτης Π. Τριανταφυλλοπούλου, αρχαιολόγος