Pottery can be very useful in the study of medieval archaeology. This is not because of the importance of the material in the society, indeed the dearth of documentary references to its manufacture and use in comparison with, for example, iron or cloth show that it had relatively little economic or social importance (Hodges, 1974). The advantages that it presents to the archaeologist over other materials are principally that it can be characterised with relative ease and once broken can only be recycled with difficulty.
The medieval potsherds on a site may represent a substantial proportion of the pottery ever used on it (compared with the minute fraction of the 'total population' represented by metal artefacts). It is likely that a similarly high proportion of these sherds came from vessels which had a short period of use, probably a few years on average (see Vince, 1977c). Therefore it is possible to reconstruct aspects of use for pottery which are not available for other types of artefact.
There are other medieval artefacts which can be characterised, for example hone stones (Ellis, 1969) and stone mortars (Dunning, 1977). It is however extremely rare to find more than half a dozen examples of either type on one site and therefore impossible to chart changes in source for such objects from one site and compare these with other sites.
Dunning examined the whole Kings Lynn collection of stone mortars and was able to show that several distinct sources were represented but even here, and this town was exceptional in the number of mortars known, there was no stratigraphic control and therefore no indication as to the relative date of the mortars.
