
Just as things got back to normal after the finish of the Gallic Empire, another usurper appeared. This was Carausius, who was emperor in Britain and northern Gaul from 287 to 293, followed by his scheming finance minister, Allectus, who was defeated in 296 by Constantius I. For the first time Roman mints were opened in Britain. In 295 or 296, Diocletian reformed the coinage, once again, with a large silver-washed bronze coin, the Follis and a new silver coin, called the Argenteus.
Most previously discovered hoards of this period, have been separate hoards of either 'legitimate' coins or local radiates, a typical example being the Prestwood 'B' hoard (Table 3, C256), which contains only coins of Diocletian and his fellow Tetrarchs and coins of the Constantinian period. However, the Rogiet hoard (Table 2, C306) and the Langtoft 'A' hoard (Table 2, C255), are fairly atypical, in that they contain not only 'reformed' coins of the Aurelianic and Diocletianic period, but also de-based radiates of the Gallic emperors and the British usurpers, Carausius and Allectus. As a result of these finds, opinion is shifting to the view that, rather than being de-monetised or simply dumped, the old radiates circulated alongside the legitimate coinage, perhaps as a different denomination.
The situation is further confused by the appearance of 'Barbarous Radiates', which start around the time of the Gallic Emperors. These were once thought to have been made by invading 'barbarians' but are now known to have been locally produced in Britain and Gaul. They are often of crude design and are sometimes much smaller than the already small official radiates. They may have been made for local use with the crude designs intended to avoid prosecution for forgery.
The Follis introduced by Diocletian lasted only until around 318, when it had been reduced to the size of the old de-based radiates. The hoards from now on (first half of Table 3) almost completely consist of bronze coins of the period of Constantine I and his extensive family (307-363). There is insufficient detail in the Treasure Reports to examine whether this phase started directly after 318. In 348 three new denominations of bronze coins were introduced and in 354 there was a general de-monetisation of older denominations. It would have been easier to de-monetise what was basically a token coinage because unlike intrinsically valuable silver coins, token coins become valueless once they are no longer 'official'. This shows in the almost complete cut-off of bronze coin hoards after the Constantinian era, with the new gold and silver hoards taking their place.
Table 3, these were the denominations that were circulating and being hoarded from the Constantinian period up to around 400. In fact 80 per cent of all late Roman silver hoards closing between 388 and 410 have been found in Britain. This is probably because once the Romans abandoned Britain, there was no possibility of people and money migrating to politically healthier climes and with an increasingly de-monetised society, nowhere to spend it.
A practise unique to Roman Britain was that of clipping of silver coins, with the clippings presumably being sold as bullion. Clipping was also rife during the English Civil War (1642-51), implying that during times of trouble, the authorities were unable or unwilling to prevent it. Clipped silver coins must have continued circulating at face value, rather than by weight, or else clipping would have been pointless. It has been suggested that silver coins were clipped to provide small change, but it would surely have been easier to cut them into halves or quarters, as was done in the medieval period. The Stanchester hoard (Table 3, C268) is one sizeable hoard where the silver coins are not clipped. Perhaps these were never circulated but were saved when new.
Given that hoarding was probably universal practise, then there is usually no way of knowing if these 5th century hoards were buried in extremis, or not. There is no way of knowing how soon after 406 they were buried, anyway. The later th