Clay was an important resource for the Iron Age and Romano-British population of eastern England as a building material as well as in the manufacture of ceramics. The micropa-laeontological and petrological signatures of potsherds from the hill fort at Burrough Hill (Leicestershire), Gamston (Nottinghamshire) and four sites in Cambridgeshire (Barley Croft Farm, Trumpington Meadows, Bradley Fen and Kings Dyke, Whittlesey) reflect the age and geological provenance of the raw materials and the firing methods. The clay used in the ceramics from Burrough Hill appears to have been sourced from the local Pleistocene glacial till (Anglian-age Oadby Member, Wolston Formation), whereas those from Gamston were probably derived from the nearby Lower Jurassic strata. Although microfossils were very rare in the material from Cambridgeshire, those found are not inconsistent with an Upper Jurassic source.