No matter who was finally responsible for the generally very good engravings of the seals, there are clear grounds for supposing that the choice of material and its organisation on the map were largely Blomefield’s responsibility. So, for example, on the right hand side is a series of seals relating to the city’s governance, shown as a sequence with a single vertical axis (Fig. 13.7). The uppermost is the earliest, made for the bailiffs of Norwich (Fig. 13.8). The matrix probably dates from between 1223 and 1226 and was almost certainly engraved by Walter de Ripa, a London goldsmith who made the great seal for Henry III in 1218 and the seal for the ‘barons’ of London, possibly in the following year.25 The latter (Fig. 13.9) shows a remarkable cityscape including two fortified towers, no doubt meant as the White Tower and Baynard’s Castle. The differences between their characterisation and the keep on the Norwich seal is instructive, as it shows two registers of external arcading, the upper with more numerous and smaller arches than the lower (Fig. 13.10). It seems that the seal engraver had been given a summary description of the most distinctive feature of Norwich castle.26