The ancient Siscia is the present Croatian city of Sisak. Its more than 2500 years of history begin in the Iron Age when a Celtic settlement called Segestica, name that would derive in Siscia, is founded in the confluence between the Kupa, Sava and Odra rivers. According to Apiano's words the city was "strongly defended by the waters, which surrounded it forming a great moat around it". In the year 35 BC Siscia is won for Rome by Octavian, the future Emperor Augustus, after a 30-day siege. Its great defensive capacity would lead it to be chosen as first order headquarter by Tiberius, the future emperor, on the occasion of the great Ilirian rebellion (6-9 AD), and against the Dacians later. In reward to its loyalty to the Empire, Vespasian elevates the city to the category of Roman colony with the name of Colonia Flavia Siscia.
Siscia retained a great ascendancy over the Illyricum region during the High Empire. This would not be the case in the Late Empire, when military needs advised to move the concentration of military and money resources to Sirmium: much closer to the Danube river than Siscia and therefore better placed strategically to coordinate the defense of the Roman frontier. As Sirmium gained importance, Siscia lost it. In fact it was Sirmium, not Siscia, the city chosen by Diocletian, at the dawn of Tetrarchy, to locate the capital of the portion of the Empire to be controlled by the Caesar Galerius. Nevertheless, Siscia always maintained a prominent importance that would continue during the Middle Ages, thanks mainly to the great capacity of its river port.
Photo 1.- Fragment of the Late Roman city-wall of Siscia.
Few are the remains of the ancient Siscia that can be seen in the current Sisak. The absence of archaeological excavations coupled with urban pressure has caused that only a few fragments of the Late Roman city-wall (photo 1) can be observed.
From the numismatic point of view Siscia begins its trajectory in AD 259, reigning the emperor Gallienus. The new mint was instituted to replace the veteran Lugdunum mint, in Gaul, which had fallen into possession of the usurper Postumus. Its main mission was always to supply numerary to the Danube border troops, for which it minted coins in the three metals. Noteworthy the volume of its bronze emissions, very high, to the point of having had up seven offices working in parallel during the reign of Probus. At the death of Constantine I the Sicia mint had five operative offices, this is, it remained fully active, minting huge amounts of coins. The progressive decline of the Western Empire would lead to a reduction in the number of offices: four (351-378), then two (378-387) and finally a single one which would be closed during the reign of Honorius (circa 413). Photos 2, 3, 4, 5, 6 and 7 will serve to know some coins struck in the mint of Siscia during the period 309 - 350.