Dion is first mentioned by the historian Thucydides, in his account of the Spartan general Vrasidas’ march to the shores of North Aegean in 424 BC, during the Peloponnesian War. Written sources and inscriptions testify that Dion was the sacred city of the Macedonian kingdom. The sanctuary of Olympian Zeus functioned as the centre of religious life and the place used by the Macedonian kings to exercise their political propaganda. At the end of the 5th century BC, King Archelaus instituted the “Olympian games at Dion”, multi-day athletic and theatrical games in honour of Zeus and the Muses, which contributed to the Panhellenic appeal of the Pierian sanctuary. A settlement was developed to the north of the sanctuary of Zeus, which initially served the needs of the cult. In an area south of the city, around the oldest sanctuaries of Olympian Zeus and Demeter, the shrines of other deities, such as Asclepius, Dionysus and Isis, were founded over time. This is also where the Hellenistic theatre and the city’s stadium were situated.
The strategic location of Dion on the north-eastern foothills of Mount Olympus – at a close distance to the shore – overlooking the passage between Macedonia and Thessaly, and the existence of the navigable river Vafyras to its eastern side prompted Cassander to fortify the city with a solid wall precinct in the end of the 4th century BC.
Philip II and Alexander the Great organised victory festivals at Dion and offered sacrifices in honour of Zeus and the Muses. Before embarking on his Asian campaign, Alexander offered splendid sacrifices at the sanctuary of Olympian Zeus, and later dedicated a magnificent bronze equestrian group by Lysippus, commemorating the twenty-five Companions (Hetairoi) who fell at the Battle of the Granicus River against the Persians. In summer 219 BC, when the king of Macedonia Philip V was engaged in war campaign in Aetolia, the Aetolian general Scopas looted Dion. Still, Philip restored the sacred city and when the Roman consul Quintus Marcius Philippus invaded Dion in 169 BC, the latter showed no traces of destruction. A year later, after the battle of Pydna, the Macedonian kingdom was abolished.
The advantages of the site and the history of the city were the reasons behind the foundation of a Roman colony at Dion by Octavian Augustus after his victory in Actium in 32/31 BC. The colony’s establishment was a turning point in the history of the city. Colonists from the Italian peninsula, who introduced the Roman political institution of tax exception and self-government as well as the issuing of coinage, reinforced its population. Under those circumstances, Dion flourished in the Imperial times especially during the reign of the Severan dynasty, when most of its public and private monumental buildings were constructed. Finally, during Late Antiquity Dion became the seat of a bishopric and comprised the main urban centre in the region of Pieria.