Blake and Lloyd rightly point out that the castle that occupies the site of Tintagel belongs to the early thirteenth century and is therefore quite irrelevant to an historical Arthur. They are absolutely wrong, however, to state that the name is not recorded before 1272, as it occurs (very obviously) in Geoffrey of Monmouth, c 1139, and is mentioned as Tintaieol in a document of 1205; the castle is first mentioned in 1235. The first element comes from an unrecorded Cornish word *dyn ‘fort’, corresponding to Welsh din, and the second element appears to be Cornish tagell, ‘throat’ (with a figurative sense here of ‘narrow neck of land’). This would be something like *Dindagell in Welsh.
There is little doubt that the construction of the castle belongs to the period after the fame of the site had spread throughout Europe. It can plausibly be connected with the creation of Richard, brother of Henry III, as Duke of Cornwall in 1227; in the 1230s, he acquired the site of the castle and then the manor of Tintagel.
The main fame of the place in the Middle Ages, though, derived from its connection with the story of Tristan and Isold, characters on the periphery of the Arthurian legend. It was said to have been the home of King Marcus (except in the poem Tristran by Béroul, who says that he also lived at Lancien); Marcus has been identified with the historical figure of Cunomorus since at least the ninth century, when the Vita Pauli Aureliani by the Breton Wrmonoch mentions Marcus, quem alio nomine quonomorium uocant (‘Marcus, whom they call by another name, Cunomorus’). Cunomorus is known as a mid-sixth century comes (‘Count’) of the Bretons, called Chonomorus by Gregory of Tours in his Historiae Francorum (iv.4). The same name is found on a memorial stone reading DRVSTAVS HIC IACIT CVNOMORI FILIVS (‘Here lies Drusta[n]us, son of Cunomorus’). All these strands of evidence place Cunomorus some time in the second quarter of the sixth century, ruling on both sides of the English Channel (but not necessarily, as most have assumed, at the same time – this was the era of migration to Brittany). A Cynfor occurs in the genealogy of the Kings of Cerniw preserved in Jesus College MS 20, pedigree 11, but so little is understood of this dynasty that it is impossible to be certain of the date of this individual. It is worth noting, though, that in a number of genealogical collections, he appears as the father of a Custennin, who is perhaps to be identified with the Constantinus of Gildas de Excidio et Conquestu Brittanniae Chapter 28.
These pieces of circumstantial evidence link a number of characters in medieval romance to Cornwall and Tintagel. However, Blake and Lloyd use Béroul’s repetition of the story about the king with horse’s ears to relocate Dindagol. The essence of the story (which originates in the Greek myth of King Minos) is that a dwarf discovered that King Marcus had horse’s ears but was sworn to secrecy; not being able to remain silent, he whispered the secret to a hawthorn bush. In a more developed version of the story known from a sixteenth-century genealogical work in Peniarth MS 134, the king is no longer King Marcus of Cornwall, but March ap Meirchion. The secret is told to the ground, which subsequently issues forth reeds that are cut for pipes which, when played in front of the king, could sing nothing but “March ap Meirchion has horse’s ears”. It is likely that the story became attached to these individuals because the Brittonic *marco- (surviving as Welsh and Cornish march and Breton marc’h) means ‘horse’. An earlier version of the story is preserved in eleventh-century Irish texts, when it is attached either to Eochu Echcend (Eochu Horsehead) or to Labraid Lorc/Loingsech (‘Seafarer’). Béroul evidently obtained his version from a Brittonic (probably Breton) source.
The story was recorded in Castellmarch on the Lleyn peninsula as late as the nineteenth century; its hereditary lords in the Middle Ages were traditionally descended from March ap Meirchion. Castellmarch certainly existed in the late 1130s, when it was mentioned by the poet Meilyr in an elegy for Gruffydd ap Cynan, King of Gwynedd. However, it is not clear if the site is named after an eponymous March or if it simply means ‘horse castle’. This is not important to Blake and Lloyd’s hypothesis: they assume (silently) that the name Dindagol was replaced with Castellmarch.
Is this legitimate? The evidence in support of both the orthodox hypothesis and Blake and Lloyd’s hypothesis is entirely circumstantial. The association between Tintagel and a Cornish Marcus with horse’s ears is found no earlier than the twelfth century; the association between Castellmarch and a North Welsh March ap Meirchion with horse’s ears is found no earlier than the sixteenth century. In terms of primacy, then, the Cornish version has the best claims. However, there is the earlier Irish tradition about a king with horse’s ears that shows that we cannot trust the legend sufficiently to allow it to give us geographical information. If we opt for primacy, then we must locate the king with horse’s ears in Ireland and, following Blake and Lloyd’s logic, seek Dindagol there. This is clearly not an option!
Are there any further clues about the location of Dindagol? Blake and Lloyd use the placename Dimilioc in Geoffrey of Monmouth (HRB viii.19-20) to make a suggestion. In the story as told by Geoffrey, Gorlois, Duke of Cornubia, flees to Dimilioc, where he is besieged by Uther Pendragon. According to Blake and Lloyd, an alternative name for this site is Caer Dunod, found in the very late Cottonian Cleopatra version of the Brut, which has been described as ‘the most individual of all the translations’ and which has borrowings from writers as late as Wace and Layamon; its use here is completely unacceptable. The name given in other versions of the Brut for Dimilioc is Tinblot. Blake and Lloyd somewhat disingenuously state that it ‘has been identified with the hillfort of Tregare Rounds in Cornwall’, when this was disproved as early as 1906. Instead, the Cornish placename Domellick locates it securely at St Dennis, where the parish church stands in a sub-Roman enclosure.
Finally, we should return to Béroul’s Tristran. This is the poem in which King Marcus is said to have horse’s ears. However, it is also the one poem where he lives both at Tintagel and at Lancien, a name Blake and Lloyd choose to ignore. Once again, though, it is a name with close Cornish connections, being borne by a farm now called Lantyan, two miles north of Castle Dore in south Cornwall. This has been known since 1912.
The case of Tintagel is supported by strong circumstantial evidence. There is not a shred of evidence in Welsh texts to suggest that Dindagol is anything other than the Brut’s rendition of Tintagel; indeed, it is not found outside those texts deriving from Geoffrey of Monmouth. The best they can do is to make a connection between a legend not recorded before the sixteenth century in the Lleyn peninsula and medieval romances. This is not the sort of evidence that can be used to rewrite the geography of fifth- and sixth-century Britain!