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Myrddin Wyllt (Welsh: ['m?rð?n 'wt]--"Myrddin the Wild") is a figure in medieval Welsh legend. A prophet and a madman, he was introduced into Arthurian legend by Geoffrey of Monmouth as Merlin the wizard, associated with the town of Carmarthen in South Wales. In Middle Welsh poetry he is accounted a chief bard, the speaker of several poems in The Black Book of Carmarthen and The Red Book of Hergest. He is called Wyllt--"the Wild"--by Elis Gruffydd, and elsewhere Myrddin Emrys ("Ambrosius"), Merlinus Caledonensis ("of Caledonia") or Merlin Sylvestris ("of the woods").
Although his legend centres on a known Celtic theme, Myrddin's legend is rooted in history, for he is said to have gone mad after the Battle of Arfderydd at Arthuret at which Rhydderch Hael of Strathclyde defeated Gwenddoleu. According to the Annales Cambriae this took place in 573. Myrddin fled into the forest, lived with the animals and received the gift of prophecy.
Myrddin Wyllt's legend closely resembles that of a north-British figure called Lailoken, which appears in Jocelyn of Furness' 12th-century Life of Kentigern, an important founder of the post-Roman church in Strathclyde, said to have died in 612. Lailoken is identified with Merlin in the late-15th-century Lailoken and Kentigern, but the alternative name may already be present in the 12th-century dialogue of Myrddin with his twin sister Gwendydd (or Gwenddydd or Languoreth), for she addresses him several times as Llallwg, for which the diminutive would be Llallwgan. Scholars differ as to the independence or identity of Lailoken and Myrddin, though there is more agreement as to Myrddin's original independence from later Welsh legends.
The earliest (pre-12th century) Welsh poems about the Myrddin legend present him as a madman living an existence in the Caledonian Forest. There he ruminates on his former existence and the disaster of the death of his lord Gwenddoleu, whom he served as bard. The poems sketch the events of the Battle of Arfderydd, where Riderch Hael, King of Alt Clut (Strathclyde) slaughtered the forces of Gwenddoleu ap Ceidio, and Myrddin went mad watching this defeat. The Annales Cambriae date this battle to 573, naming Gwenddoleu's adversaries as the sons of Eliffer, presumably Gwrgi and Peredur. This battle, the subsequent assassination of Urien Rheged and the defeat of the Gododdin at Catraeth are cited as reasons for the collapse of the alliance of early British kingdoms in the north before the Angles, Scots and Picts.
A version of this legend is preserved in the late-15th-century Lailoken and Kentigern. In this narrative St. Kentigern meets a naked, hairy madman called Lailoken, said by some to be called Merlynum or Merlin, in a deserted place. He has been condemned for his sins to wander in the company of beasts, having been the cause of the deaths of all of the persons killed in the battle fought on the plain between Liddel and Carwannok. Having told his story, the madman leaps up and flees from the presence of the saint back into the wilderness. He appears several times more in the narrative until at last asking St. Kentigern for the Sacrament, prophesying that he was about to die a triple death. After some hesitation, the saint grants the madman's wish, and later that day the shepherds of King Meldred capture him, beat him with clubs, then cast him into the river Tweed where his body is pierced by a stake, thus fulfilling his prophecy.
Legend has it that second part of Carmarthen's name (in Welsh -fyrddin) was derived from Myrddin and identified his place of birth. However, when Britannia was a Roman province, Carmarthen was the civitas capital of the Demetae tribe, known as Moridunum (from Brittonic *mori-dunon meaning "sea fort"), and this is the true source of the town's name. Celticist A. O. H. Jarman suggests that instead the name Myrddin was derived from Carmarthen's name.
Welsh literature has examples of a prophetic literature, predicting the military victory of all of the Celtic peoples of Great Britain who will join together and drive the English - and later the Normans - back into the sea. Some of these works were presented as prophecies of Myrddin; while others such as the Armes Prydein were not. The tradition was apparently shared with Cornish literature, however only a single Latin translation of a lost Cornish-language original Prophecy of Merlin exists in the Vatican library by John of Cornwall.
The modern depiction of Merlin began with Geoffrey of Monmouth. His book Prophetiae Merlini was intended to be a collection of the prophecies of the Welsh figure of Myrddin, whom he called Merlin. He included the Prophetiae in his more famous second work, the Historia Regum Britanniae. In this work, however, he constructed an account of Merlin's life that placed him in the time of Aurelius Ambrosius and King Arthur, decades before the lifetime of Myrddin Wyllt. He also attached to him an episode originally ascribed to Ambrosius, and others that appear to be of his own invention.
Geoffrey later wrote the Vita Merlini, an account based more closely on the earlier Welsh stories about Myrddin and his experiences at Arfderyd, and explained that the action was taking place long after Merlin's involvement with Arthur. However, the Vita Merlini did not prove popular enough to counter the version of Merlin in the Historia, which went on to influence most later accounts of the character. One exception to this is the work of Count Nikolai Tolstoy titled The Coming of the King.