Ninth-century Kentish Old English <b>/<B>, where it represents a reflex of Germanic [ß], has hitherto been dismissed as an orthographic ‘archaism’. Here, however, it is argued that the graph is a genuine reflection of ninth-century Kentish phonology. The linguistic argument, which invokes the concept of neutralization in reconstructing the Old English obstruent system, is placed in the context of reconstructions of the external history of Kent. Data are drawn from forms of moneyers' names on early Anglo-Saxon coins, discussed in the context of interpretations of manuscript data.