Dion in Pieria was the sacred city of the Macedonian kingdom. The sanctuary of Olympian Zeus functioned as the center of religious life and the place used by the Macedonian kings to exercise their political propaganda. In the end of the 5th century BC., at king Archelaos’ initiative the “Olympian games at Dion”, athletic and theatrical contests in honor of Zeus and the Muses that lasted several days, were established which contributed to the panhellenic appeal of the Pierian sanctuary. A settlement was developed to the north of the sanctuary of the Olympian Zeus that initially served the cult’s needs.

The strategic location of Dion on the northeastern slopes of Mt Olympus -at a close distance to the shore and the navigable river Vafyras to its eastern side- overlooking the passage between Macedonia and Thessaly prompted Kasssander to fortify the city with a solid wall precinct in the end of the 4th century BC.

Philip II and Alexander the Great organized at Dion victory festivities, offered magnificent sacrifices and made rich dedications in honor of Zeus and the Muses. 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 of the Macedonians and when the Roman consul Quintus Marcius Philippus, invaded the city in 169 BC the latter showed no traces of destruction.

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 the victory in Actium in 32/31 BC. The colony’s establishment was a turning point in the history of the city. Its population was reinforced by colonists from the Italian peninsula, who introduced the Roman political institution of tax exemption and self-government, as well as the issuing of coinage. 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 a bishopric and comprised an important urban centre in Pieria.

The Episcopal Basilica of Dion

The Episcopal Basilica of Dion was built at the west of the Roman Forum of Dion. The basilica had two successive building phases, the first dating from the end of the 4th century CE till the beginning of the 5th century CE, and the second one during the second half of the 5th century CE.

The former church comprises of a three-aisled basilica with narthex. Fragments of murals testify that its interior was adorned with painted decoration, while the floor was covered with mosaics, consisting of geometric patterns. After few decades, this church was replaced by a new one, whose floor was raised by approximately 2 m. This new basilica had an atrium with three stoas. In the central room of its west wing, which served as a baptistry, there was a baptismal font shaped like a cross.