Copper 'as' of the emperor Hadrian
After the invasion of AD43 there must have been great demand for the low value bronze (orichalcum and copper) coinage since the coins were imitated in large numbers. Presumably this was because there was not a large enough supply coming from the mint in Rome (there was no official mint in Britain until the late 3rd century). The local copies were often very crude but were produced in large numbers. This coin would have bought a loaf of bread. Interestingly, Roman coins are found less frequently on rural sites than on urban sites, which implies they were used more in towns than in the country.