The composition of ‘naturally coloured’ late Roman vessel glass from Britain and the implications for models of glass production and supply

Naturally coloured, blue or green are the most common glass colours found in assemblages from the Roman world from the end of the 1st century BC onwards. In the 4th century two different compositions have come to dominate this group, ‘HIMT’ and ‘Levantine 1’ glasses, both of which are now thought to have been produced in the eastern Mediterranean. Using Romano-British glass assemblages from the 4th and 5th centuries, it is shown here that although the two naturally coloured glass types predominate, by far the most common composition in British assemblages is HIMT, although older, earlier blue-green compositions are still present. The earliest date HIMT could be identified in these assemblages is around AD 330, although two distinct compositions can be identified within this group which relate to changes in composition over time. A similar change over time is seen in the Levantine 1 glasses. The reasons for these patterns within the assemblages are explored within the archaeological evidence currently available for glass production and consumption in the Roman world.