Tintagel has been associated with King Arthur for a millennium, particularly after Geoffrey of Monmouth wrote and published his History of the Kings of Britain in the early 12th century. Though now often claimed as the site of Arthur’s court or castle, Geoffrey cited Tintagel merely as the site of Arthur’s conception.
Uthr, Uthyr, Uther
Uther Pendragon, whose last name derives from a Welsh title pen dragon or pen draig (‘head dragon’ or ‘chief warrior’), is a rather strange and shadowy figure. His chief claims to fame are his sobriquet Pendragon and his being the father of King Arthur. In the 11th-century Welsh poem numbered 31 in the Black Book of Carmarthen — Pa Gur (‘Which man?’) — he appears as uthir pen dragon, a warrior whose servant is in Arthur’s retinue: uthr in modern Welsh means wonderful or terrible, perhaps even awesome in the sense of ‘producing awe’. 
According to Geoffrey of Monmouth (c 1095-1155) the name Pendragon came from a comet which supposedly gave Uther victory over the Saxons.  Geoffrey may have had in mind a comet of 508 with several tails, or may even himself have remembered a spectacularly brilliant comet of 1106, noted in a Welsh chronicle as “a star wonderful to behold, throwing out behind it a beam of light of the thickness of a pillar in size and of exceeding brightness, foreboding what would come to pass in the future”. 
The word dragon in Welsh seems to have been a customary title for a warrior, however, as Maelgwn of Gwynedd (d 547) was called by his contemporary Gildas ‘the dragon of the island’, insularis draco (possibly Gildas meant the isle of Anglesey).  A plausible suggestion has been that Uther is therefore a ‘ghost’ and that the person in Arthur’s retinue mentioned in Pa Gur is merely the servant of uthir pen dragon, the ‘fierce chief warrior’.
In the medieval Welsh Triads  we are given a suggestion of other traditions about Uthyr (in collections datable to the late 13th century). One of the Three Great Enchantments of the Island of Britain, for example, was caused by Uthyr Pendragon which he taught to Menw son of Teirgwaedd (‘little son of Three Cries’). This Menw is known also from the medieval tale Culhwch and Olwen — written down in the 11th or, more probably, 12th century — in which he too is a great enchanter: “should he come to a heathen land [Menw] might cast a spell over [Arthur’s men], so that none might see them and they see everyone.” Menw also casts a calming spell over a giant mastiff and transforms himself into the likeness of a bird. 
In Geoffrey’s History these meagre hints at Uthyr’s magical powers are given much more substance. Uther is advised by one of his colleagues, Ulfin of Ridcaradoch, and by Merlin. The latter, by the use of drugs (“methods which are quite new and until now unheard of in your day”) gives Uther the likeness of Duke Gorlois of Cornwall, and also disguises Ulfin as Jordan of Tintagel and Merlin himself as Britaelis. By this deception Uther gains access to Gorlois’ wife Ygerna (with whom he has become infatuated) and Arthur is thereby conceived. 
So the obvious feature shared by both the Welsh Uthyr and Geoffrey’s Uther is shape-shifting: Uthyr, remember, is a great enchanter (he teaches Menw, himself not only a great enchanter but also a shape-shifter) while Uther has his appearance changed into that of Ygerna’s husband. The main development now is that the shape-shifting is brought about by Merlin, not by Uther himself (assuming of course that tales of Uthyr preceded those of Uther). Geoffrey rationalises the change by his use of drugs and not spells.
The most striking parallel to Geoffrey’s version of Arthur’s conception however is in the early medieval Romance of Alexander, drawn from Near Eastern oral tradition, and it is to this romance that we now turn.
Nectanebo, Nectanebos, Nectanebus
The last native-born ‘king of Egypt’ is Nectanebos, a royal sorcerer. While in disguise in Macedonia he becomes infatuated with Olympias the queen, and tells her that she will mate with the Egyptian god Ammon. Ammon is “white haired, with the horns of a ram above his jaws”. The first harbinger of the god is to be a serpent who slithers into her room in the palace. Needless to say it is Nectanebos who, disguised as Ammon, is responsible for Alexander the Great’s conception and not Philip, Olympias’ husband. 
Nectanebus went forth from the royal palace, and went out swiftly and speedily to the plain. Then he hastened to the desert, and gathered those roots which men use for dreams, and he pounded and pressed them all; and in a dream of the night Nectanebus by his magic sent to Olympias what she desired, so that in her dream she thought that she was actually sleeping with the god Ammon, and that he was embracing her, and that of his own free will he abode with her, and that when he had done with her he said to her, “O woman, behold, thy womb will avenge thee.”
There is no doubt that Geoffrey would have been aware of this very popular medieval tale with its hero conceived by a shape-shifting king (complete with ram’s horns and serpents) on a queen in her royal palace. The analogy with Uther Pendragon is striking, and the image suggests a horned magician grasping a ram-headed serpent, as in the Danish Gundestrup cauldron. We might need look no further for the source of the tale of Arthur’s origins.
The fact is, however, that this kind of mysterious conception occurs in all kinds of cultures and all manner of religions. Here are the relevant parts of a list compiled concerning the births of Celtic heroes (here with Arthur as exemplar): 
- The advent and future greatness of the hero have been foretold (Merlin’s prophecy of the Boar of Cornwall)
- His advent is destined to bring death or misfortune to a presiding power (the Saxons)
- Certain difficulties have to be overcome before his future mother can fulfil her destiny; she is closely guarded, confined in a fortress (Tintagel) and her own resistance has to be overcome by cunning (Uther’s disguise)
- There is a mystery about the hero’s begetting; whether he has an earthly father or not, he is usually begotten by another — a king, a man from another race, or a supernatural being (there seem to be echoes of Arthur’s dubious origin when the 9th-century Nennius says he was war-leader “though there were many more noble than he”). 
Igerna, Ygerna, Eigr, Eigr
We have also to consider the role of Ygerna or Igerna, in Welsh Eygr or Eigr. She is later claimed as the aunt of St Illtud (whose biography also claims he is Arthur’s cousin) and given a respectable royal ancestry but in truth we know little about her. Victor Canning’s novel The Crimson Chalice (1976) gives her a setting on Lundy Island in the Bristol Channel, I assume because of a 6th-century memorial tombstone reading … IGERNI … I TIGERNI.
But Charles Thomas suggests restoring this as CONTIGERNI or VORTIGERNI FILI TIGERNI (‘the stone of Contigernos / Vortigernos, the son of Tigernos’).  Tigernos in Celtic meant ‘ruler’ or ‘king’, givimg rise to the archaic Welsh term teyrn and, via Irish, the English surname Tierney; it may well be cognate with the Latin tyrannus. While it’s tempting to imagine that Igerna’s name is somehow related to or derived from tigernos I think it’s merely a will-o’-the-wisp notion at the moment.
While Geoffrey may have known of the IGERNI stone on Lundy there doesn’t seem to be a general association of Ygerna with Lundy. What about Tintagel then?
The once plausible suggestion  was that Geoffrey “wrote when the first Norman castle was being built,” but further excavations since the 1930s have shown that the island wasn’t the site of a Celtic monastery as first proposed and that the castle was probably built in the 13th century in the knowledge of growing interest in the literary Arthurian associations. But excavations from the 1990s onwards have established that Tintagel was a site of some strategic importance in the post-Roman period with enough clout to import a significant amount of goods from across the Mediterranean. We may wonder if a lingering memory of this period, half a millennium before Geoffrey wrote his History, suggested the promontory as the site of Ygerna’s seduction with a scenario inspired by The Romance of Alexander.
Back in 1980 I indulged in a bit of speculation which, unfortunately, may not have stood the test of time or evidence, but I mention it here for its possible interest.
Two mazes, about a palm’s width across, were found carved into the cliffs at nearby Rocky Valley in the twentieth century. They were tentatively dated to the Bronze Age at the earliest, and their uniqueness as rock carvings in Britain, coupled with their proximity to Tintagel, raised the possibility that some genuine tradition concerning them prompted Geoffrey to locate the conception of Arthur here and nowhere else.
Three popular studies, by Rachel Levy, W H Matthews and Jack Lindsay,  touched on the significance of maze rituals in preliterate cultures. In the ancient Mediterranean the maze-dance served related rites, scholars suggest: first it set up magical defences against the entry of the initiated into the sacred city (for instance at Troy), and second it was the preparatory ritual for gaining access to the earth goddess and performing the Sacred Marriage (as these writers proposed with the Cretan labyrinth). In the South Pacific islands of the New Hebrides (Malekula in particular) labyrinthine dances are also very clearly related to death-and-resurrection ceremonies. Are all these conditions found fulfilled at Tintagel? I note that Uther is told by Ulfin that
“No power on earth can enable us to come to her [Ygerna] where she is inside the fortress of Tintagel. […] There is no other way in except that offered by a narrow isthmus of rock. Three armed soldiers could hold it against you…”
Geoffrey is here echoing an early Roman legend, in which just three men, including Horatius Cocles, defended the Sublicius bridge over the Tiber against the might of the Etruscan army, just long enough that the bridge behind could be destroyed and Rome saved from the invaders. Horatius waited till the last moment before diving into the river and escaping further hurt.
But by Merlin’s deception three unarmed men gain entry without bloodshed, for when Uther, Merlin and Ulfin approached the entrance the guard “opened the gate and the men were let in” — almost as happened with the wooden horse of Troy. Uther then comes to Ygerna saying he has secretly escaped from a siege, concerned as he was with the safety of her person and of his castle. She, in her turn, “refused him nothing.”
Simultaneously (and this may be significant) Gorlois, Ygerna’s husband and Duke of Cornwall, is killed as he tries to break out from his besieged camp.
The capture of ancient Troy was imagined as the symbolic rape of its patron goddess Athena: the palladium, a cult wooden figurine of Pallas Athena, was stolen by Odysseus and Diomedes from the Trojan citadel after they’d entered by a secret passage. This led to the successful episode of the Trojan horse and Troy’s eventual sacking; it also resulted in the retrieval of Helen from her abductor back to her husband Menelaus, her abduction being the cause for the Trojan War. Here we have the breaching of a citadel by stealth and involving the capture (‘rapine’) of a female in human or figurative form. Though more violent than in Geoffrey’s story there are certain parallels.
According to Plutarch’s Life of Theseus, after the hero had killed the Minotaur and eloped with Ariadne,
on his voyage from Crete, Theseus put in at Delos, and having sacrificed to the god and dedicated in his temple the image of Aphrodite which he had received from Ariadne, he danced with his youths a dance which they say is still performed by the Delians, being an imitation of the circling passages in the Labyrinth, and consisting of certain rhythmic involutions and evolutions. This kind of dance, as Dicaearchus tells us, is called by the Delians The Crane, and Theseus danced it round the altar called Keraton, which is constructed of horns (‘kerata’) taken entirely from the left side of the head.
Whether the geranos, ‘crane dance’ or dance of the Cretan labyrinth, was expected to lead to the sacred marriage of Theseus with Ariadne (who might or might not have been a Cretan goddess) can only be speculative. But here is a similar situation to Troy: the winding dance, as though entering a city, the involvement of a female (Ariadne) or figurine (an image of Aphrodite taken, like Ariadne, from Crete) compares with a perilous journey into a city and the capture, by force or by cunning, of the female representing the sovereignty of that place.
Are the circumstances of the events at Tintagel not that far distant? Geoffrey clothes his story as historical romance. But if he visited Tintagel (as his quite detailed description suggests is possible) he could have been made aware of a local folk custom involving a processional dance, or maybe a seasonal mumming play with its death-and-resurrection / sacred marriage rituals, and possibly a hobby horse. We have only to look a little further down the coast to see Padstow’s May Day rites which, against all odds, are still celebrated with great vigour at the present day.
Sadly the Rocky Valley labyrinths, formerly believed to be Bronze Age, have been examined closely and are said to have been made with metal tools, suggesting a much more recent date. But, given the coincidences listed above, was a similar ritual to the Padstow May Day ceremonies what inspired Geoffrey to add his classical touches? Did he see Ygerna of Tintagel as a kind of British Helen of Troy or Cretan Ariadne?
Revised, expanded and updated from ‘King Arthur’s Tintagel’ published August 1980 in Pendragon, the Journal of the Pendragon Society XIII/4, 21-23.
 Jon B Coe and Simon Young, The Celtic Sources for the Arthurian Legend. Llanerch Publishers 1995: 128-9
 Geoffrey of Monmouth, translated by L Thorpe, The History of the Kings of Britain. Penguin 1966: 200-1
 R Ash and I Grant, Comets. London 1973: 40
 T Jones and G Jones, The Mabinogion. Dent 1949
 The History of the Kings of Britain 207
 E L Ranelagh, The Past We Share. Quartet Books 1979
 A Rees and B Rees, Celtic Heritage. Thames & Hudson 1961: 223
 Nennius, translated by John Morris, British History and the Welsh Annals. Phillimore 1980: 35 gives a standard version; my quote is from a variant
 Charles Thomas, ‘Tintagel’, Current Archaeology 16, September 1969; Charles Thomas, And Shall These Mute Stones Speak? Post-Roman inscriptions in Western Britain. University of Wales Press 1994: 165-6.
 C A Ralegh Radford, Tintagel Castle. HMSO 2nd edition 1939: 6; O J Padel, ‘South-western sites with Arthurian associations’ in The Arthur of the Welsh. The Arthurian Legend in Medieval Welsh Literature edited by Rachel Bromwich, A O H Jarman, Brynley F Roberts. University of Wales Press 1991: 229-234
 G Rachel Levy, The Gate of Horn. Faber 1949; W H Matthews, Mazes and labyrinths, their history and development, Dover 1970; Jack Lindsay, Helen of Troy. Constable 1974