Founded with the name of Perinthos at the end of the 7th century BC, Heraclea was an ancient city of Thrace, now defunct, whose remains rest under the buildings of the Turkish city of Marmara Ereglisi.
Its strategic position on the Marmara Sea coast, halfway between the straits of the Bosphorus and the Dardanelles, facilitated its economic development, constituting for centuries a prosperous commercial enclave. Its historical rival was Byzantium: a city never surpassed by Heraclea in wealth but yes in terms of ability to thrive within Roman politics. Efectively, the chronicles emphasize that Byzantium was always considered too independent for the Roman canons unlike the quite more submissive Heraclea. This is the reason why this latter was named capital of the Thracian diocese instead of the powerful Byzantium. It also explains why, on the occasion of the Diocletian monetary reorganization, put on the table the need to install an imperial mint that would supply the Diocese of Thrace, was chosen Heraclea, the diocesan capital, and not Byzantium, to house it.
During the first and second tetrarchies Heraclea coined large quantities of bronzes and some silver and gold, being the findings of coins issued in this mint extremely common in the present Bulgaria and in the European Turkey. It maintained five workshops or officinas working in parallel until the reign of Licinius I (AD 308-324).
The "foundation" of Constantinople by Constantine I marks the beginning of the decline of Heraclea as a city. As the first one grows and develops, Heraclea loses importance until there comes a time when the city is completely overshadowed by the descendant of what was once its greatest commercial rival (Byzantium). In the numismatic plane the decline of Heraclea is reflected in a gradual decrease in its volume of mintage, more and more pronounced as the Constantinople mint production increases. However, during the government of the Constantinian dynasty there was not too great a decline: the five monetary workshops continued opened and the volume of minting kept up. This suggests that Heraclea mint was functioning as an auxiliary to the constantinopolitan one during decades. From the Julian the Apostate reign onwards the decay sharpens, being reducied to two the number of minting offices. The division of the Empire into two parts brings with it the definitive election of Constantinople as capital of the eastern half and with it the final decline of Heraclea, reduced thereafter to the status of a developed provincial city. Consequence of this is a marked decrease in the total volume of coins issued by the two officinas of the mint, clearly reflected in its greater rarity in comparison with the same types coined in the main mints of the period. Finally the Heraclea mint will be closed at the dawn of the Byzantine Empire, ruling in Constantinople the emperor Leo I (457-474). It would never be opened again.
The Heraclea mint issues are characterized by their careful art and quite pure Balkan style. It is noted that the successive generations of artisans who worked in their workshops knew their trade well. The coins in photos 10, 11, 12, 13 and 14 will serve to illustrate the work of these people:
Photo 1.- Post-reform radiated coined on behalf of Diocletian in the second office of Heraclea during the triennium AD 295-297. Post-reform radiate is a modern name, strictly descriptive, with which this divisor of the follis (without silver in its composition, introduced by Diocletian in the Roman metrological system) is denominated. It is estimated that 1 follis equaled to 5 radiated. Post-reform radiated was not coined in all the imperial mints, highlighting among those that did, by the large volume of radiates emitted, the mints of Alexandria, Cyzicus and Heraclea.