The 'white' or buff earthenware body of this jug is characteristic of the clay used in the potteries centred in and around Kingston-on-Thames in Surrey. Collectively, the ceramic products produced in these potteries are known as 'Surrey whitewares'. Excavations in Kingston have uncovered several kilns, datable to the second half of the 13th century. This dating ties in well with surviving documentary evidence which shows that Kingston potteries were supplying London with ceramic products from the 1250s. On several occasions, Kingston also supplied the royal household with large numbers of drinking and serving jugs.

This jug is partially covered with a green-coloured glaze. The green is produced by adding copper filings to the simple colourless lead glaze. The coloured glaze is a pleasing and more costly decorative feature and would indicate that the jug was meant to be displayed and used at the table rather than used in the kitchen.

The jug bears armorial stamps, all showing a shield displayed with three chevrons. This is another indication that the jug was meant to be displayed or used in fine dining. This armorial bearing is known only on two other jugs, both of which are now in the Museum of London. All three of these jugs were found within the medieval city boundary of London. A pottery fragment with these arms was excavated at a kiln site in Kingston and thus strengthens the connection between these jugs and the pottery production centres along the banks of the Thames.

The arms on the shield were identified in the 19th century as those of the De Clare family, Earls of Goucester. Their arms are recorded as:
Or, three chevrons gules (three red chevrons on a gold ground)
None of the arms on the three jugs bear any colouring and so the identification with the de Clare family must always remain speculative. There are several other families who also bear these arms but with different tinctures or colourings. Only one of these has any direct connections with London and with properties in the medieval City of London. Walter de Manny (1310-1371/2), related to the Count of Hainault, accompanied Phillipa, the future wife of King Edward III (reigned 1327 to 1377), to England. He remained in this country and served in the Queen's household as well as in Edward's military campaigns in Scotland and on the Continent. His arms are recorded as:
Or, three chevrons sable (three black chevrons on a gold ground)

Different types of jug shapes were produced over long periods of time. This type of jug, described as 'conical', was made from the second half of the 13th century and is found as late as the end of the 14th century. However, conical jugs with relief decoration have so far only been excavated in late 13th and early 14th century contexts. The fragment excavated in Kingston with the chevron arms came from an early 14th century context.

This would strengthen the assumption that the arms are of the De Clare family who were active in the London area from the second half of the 13th century. In 1290 Gilbert de Clare married the daughter of King Edward I (reigned 1272 to 1307). Their son, also Gilbert, succeeded to the earldom in 1295. He died at the Battle of Bannockburn in 1314, leaving no heirs. If the jug does indeed because of its shape and relief decoration date no later than the early part of the 14th century, then the arms would be of the De Clare family rather than of Walter Manny who lived later in the century.