THE EARLY MIDDLE AGES, Romano-British, Kings of Dumnonia, cast Potin, c. 420-60, diademed and bearded head left, traces of legend in front, rev. standing figure holding curved staff in right hand and uncertain object in left, chamfered rim, 7.77g/1h (cf. Mitchener, Jetons, Medalets and Tokens I, p.7 [citing an example found at Billingsgate, London in deposits c. 420-60]; cf. BMC Bronze Coins of Gaul 338-69 obv., 482-506 rev.). Extremely fine and extremely rare £150-200

In 410 Honorius, being pressed by the barbarians in Italy, told the Britons that they must henceforth defend themselves against the Picts, Scots and Saxons; from this time on Britain ceased to be a Roman province. The Brythonic kingdom or kingdoms of Dumnonia survived the post Roman chaotic period in the south-west of ‘Greater Britain’, a region noteworthy for its many hill forts such as Cadbury Castle and high-status settlements like Din-Tagell (modern Tintagel), which were refortified and rebuilt. The capital was almost certainly Isca Dumnoniorum (Exeter) and the main economic activity was the mining of tin, exported from the port of Ictis (St Michael's Mount). The earliest historical source for Dumnonia is Gildas (De excidio et conquestu Britanniae, 28), who informs us that it was ruled by a tyrant named Constantine, who appears in later Welsh genealogies as Custennin, son of Cynfawr, and in Geoffrey of Monmouth’s Historia Brittonum as Constantine, son of Duke Cador of Cornwall, who in Arthurian legend is King Arthur’s cousin and successor.

The reference is Mitchener p.71, 83 [citing a similar example inscribed REX ALPHO]; the legend Rex/Alpho may refer to a certain 5th century British ruler named Elafius, mentioned as being regionis illius primus or 'leader of that region' in Constantius of Lyon's hagiography of St Germanus (chs. 26 and 27) and Bede's Ecclesiastical History of England (ch. 21)