The Domitian II Coin from Chalgrove: A Gallic Emperor Returns to History
Abdy, Richard, Antiquity
The Gallic Empire
The year AD 260 saw arguably Rome's greatest military humiliation: the capture of Valerian, the senior reigning emperor, by the Sassanian Persian Empire. The repercussions stretched across the Roman world. The eastern campaign was lost and the situation was only stabilised by the rise of Palmyra (which itself soon showed separatist tendencies). In the west, Valerian's son Gallienus had to contend with a more direct challenge to his dynasty, which was now stigmatised by the scandal of his father's enslavement. Gallienus's son Saloninus had been left in charge of the Rhine forces but was soon confronted and assassinated by one of his own officers, Postumus. This left the emperor at Rome facing a power block almost as large and powerful as his own: the Gallic Empire. Postumus, as the emperor of this new regime, adopted all the trappings of the 'Central' Empire. This included a copious coinage which tells us that he took titles in imitation of the legitimate emperor while archaeology (see below) presents a picture of a parallel court at Trier with a Praetorian Guard headed by his eventual successor Victorinus. Postumus faced rebellion on the frontier headed by Laelian who was swiftly dealt with, but was brought down by the hostility of his own troops when he refused to allow them to loot the city of Mainz which had been the stronghold of his foe (AD 269). A brief interlude under Marius followed but within the year Victorinus was in charge. His realm was smaller than that of Postumus, for Spain had refused to recognise him and had returned to the fold of the central authority. Victorinus was also to lose control of the Rhone and Raetia, but the Gallic Empire limped on, with power passing to the last usurper in the form of Gaius Pius Esuvius Tetricus and his young son in AD 271. (Victorinus's demise was reportedly due to his outrageous conduct towards his courtiers' wives.) It took the exceptional military skills of Aurelian (AD 270-5) to re-unite the empire. Surprisingly, Tetricus's defeat at Chalons-sur-Marne in AD 274 resulted, not in death, but retirement to a governorship in the south of Italy. He lived into old age in contrast to Aurelian, who was assassinated the year following his great achievement.
Gallic Empire coins
The main denomination of coins produced for the Gallic Empire in the third century show a bust of the emperor surmounted by rays of the sun, and are today termed 'radiates' in lieu of their ancient name. They are often considered the most miserable coin types of the whole Roman series. Even at its inception in AD 215 the denomination was an alloy of only below half silver and had to be treated in a process of surface enrichment to maintain a deceitfully silvery sheen. Such a process involves the coin blank being dipped in acid to leach out the base material from just the surface of the alloy, leaving the silver (Ponting pers. comm.). By the AD 260s the amount of silver in the alloy had sunk to below five per cent and had to be disguised with a thin surface wash of silver (usually lost during archaeological burial if not sweated off beforehand in a nefarious process known to have been proscribed in antiquity). Alongside the progressive silver debasement of the third-century radiate went a massive increase in production and decline in quality control.
Radiate hoards are regularly unearthed in Britain, especially by detectorists, and make up the majority of the 50+ coin treasure cases seen annually by the British Museum. The largest British coin hoard from any period of the island's history was the 54 951 radiates found at Mildenhall, Wiltshire at the site of the Roman town of Cunetio. Discovered in 1978, the Cunetio hoard was subsequently acquired by the British Museum. Its catalogue (Besly & Bland 1983) made a considerable contribution to our knowledge of third-century radiates. This was followed by the discovery of 47 909 radiates at Normanby, Lincolnshire in 1985 (catalogue by Bland & Burnett 1988). …