Pottery Dating

Clevedon & District Archaeological Society

David Dawson – ‘Pots – Evidence of Dating and so much more’

David’s starting point was ‘caution’, taking care not to take things at face value.Some pots and plates have dates etched or glazed on them, but what do these really tell us? Was it a presentation or commemoration piece, and is this the date of the event or the date of a person’s birth, marriage, etc which might bemany years earlier? Even maker’s marks can be misleading. Pountney & Co used a mark of crossed swords with the date 1652 from 1945-57, but the date is from archaeological evidence indicating the date of the Temple pottery in St Anne’s, Brislington but linking this date with Pountney’s name is dubious.

This piece has a second date of 1648 to confuse further.

In the ground what is found – like many of us digging even in our own gardens – is a lot of tiny ceramic fragments. It is really quite rate to retrieve sufficient pieces to get anywhere near a complete artefact. It take a lot of practice to identify the shape and end purpose of pottery from shards. Even then the stratigraphy of a site is probably the most important tool in being able to date pottery.

William Flinders Petrie was the first to set out to classify pots and established a sequence dating system – contextual seriation theory – by painstakingly linking pottery styles to the reigns of Pharaohs. This provided the first attempt at relative dating in the late 19th century.

Around the same time Pitt Rivers was progressing his whole site excavation methods based on geological principles. Unfortunately achieving this through spit digging precluded a full understanding of stratigraphy and the ability to place artefacts in their correct stratigraphic location.

Works published by Dragendorf on samian ware typology (1891) and Dressel on amphorae (1899) became standard references outside their original find areas. It was perhaps by chance that the standards worked for Great Britain due to the level of imported goods during Roman period.

Dressel chart of Roman amphora forms in Rome

It was not until the 1950/60’s that other forms of dating became available. Ken Barton and Gerald Duffy (Medieval Pottery Society founders) commenced early studies. Barton’s excavations at Ham Green (1963/64) identified Saintongeware - very large early medieval hand built jugs - imported from France.

Saintonge jug

Barton visited France and was able, through the range of pottery made along the Atlantic seaboard and exported to Britain, to not only demonstrate the extent ofthe wine trade through Bristol, but expand considerably knowledge for relative dating.

Later excavations at Dundas Wharf, Bristol (1982/3) extended dendrochronology sequences and allowed these dates to be linked to pottery finds. The period ofproduction of the Ham Green kiln was originally thought to date to the 13th century, but Ham Green sherds from archaeological contexts at Dundas Wharf inBristol, closely dated by tree-ring analysis of associated timbers, now indicate a date range from about 1120 to 1275 (Ponsford 1991, 84-86).

Pottery virtually disappears from the record from around 650-950AD and when it reappears is much cruder. Rahtz (1974) identified a series of ‘baggy’ shaped open necked jars found at Glastonbury as dating to the late Saxon period.

The identification of pottery requires a very close examination of the fabric – type of clay and inclusions as well as form and style. Excavations at TauntonCastle produced as series totally more than 270 fabrics. Pottery with a distinctive fabric found during excavations near Redcliffe Cathedral (mid 1970’s) was able to be dated from 1250 to c. 1390 and some even assigned to a specific potter.

Associations also help in identifying pottery. At Wells Museum a pit excavation, established the pit filling as a single archaeological event, and allowed all artefacts found to be associated as in use during a specific period.

Bristol pottery sequences are now well established and used for identification of pieces found from a wide area. There is a great network of relative datesforming a jigsaw of sorts into which it is occasionally possible to fit a specific date.

Using shard fragments to discern the end shape and use of pottery is very difficult. A variety of jars found in the choirs of a number of churches tooksome time to be identified as having a specific use – set into the walls to improve acoustics. They were eventually found to have a finer fabric and body thicknessbut in other respects were similar to standard cooking/storage pots. Jugs used for wine and beer have a distinctive difference, in part due to the medieval class system with only top table being served wine.

The addition of inclusions helped to make cooking pots shatterproof to deal with direct contact with fire. The ability to distinguish different types of inclusion assists in determining the end use.

The hierarchies of materials used at the medieval table allow associations to be made. Drinking vessels ranged from gold and silver, through bronze to pottery, wood and leather. No pottery plates were used until the late 17th century, the majority probably being wood. The same distinction applied in the kitchenwith bronze being most expensive items, then iron followed by pottery and treen (wooden).

A sealed stratigraphy can provide a benchmark in relative dating. The most helpful are those provided by a single, catastrophic event such as a shipwreck of major fire. The loss of the the Mary Rose in 1545 and the newly launched Vasa in 1628 in Sweden both provide unique preservation of not only pottery butassociated finds often lost through erosion on land. Similarly thedestruction of a farmstead at Dinna Moors, Dartmoor through fire around 1350 after which it was abandoned, with wooden and pottery vessels discovered during 1960’s
excavations.

More recently mineralogical composition of clays can be compared kiln site by kiln site providing further extending the relative dating process.