The Origin of Merlin
Although the character of Merlin first appears in Geoffrey of Monmouth's fanciful medieval history, he appears to be a composite character based on two separate historical characters: Myrddn, a magician/prophet mentioned in earlier poetic tales, and Ambrosius Aurelianus, a fifth century Romano-British war leader. Myrddn, who might be considered the earliest incarnation of Merlin, was not a wizard but a Welsh warrior bard who received the gift of prophecy as a result of madness caused by the grief of losing his loved ones on the battlefield. Myrddn is described as living among the forest creatures until he obtains the gift of prophecy. (This early origin tale is echoed in later tales of Merlin, where he is said to have lived his final days as a wild madman in the forest.) Myrddn is himself a very curious character, perhaps a druid. One telling story of Myrddn claims that he prophesied his own triple death by beating, drowning, and impalement — a fate not unlike that of certain sacrificial victims. Geoffrey calls his composite creation Merlin Ambrosius.
In later versions of Merlin's biography, it was claimed that his mother was a nun in a convent who was seduced by the devil himself, in order to beget an antichrist. The pious nun repented and foiled the plan by having the child baptized immediately upon his birth.
To further muddy the waters, Ambrosius Aurelianus is one of the leading candidates for the role of the historical Arthur. Little is known of the biography of Aurelianus except that he was Roman by lineage and the survivor of a great onslaught by the Saxons. He organized the remainder of the Britons and achieved a number of victories against the invaders. It is unclear why Geoffrey identifies Merlin and Aurelianus, except that both Myrddn and Aurelianus figure in stories about Vortigern, another early ruler.
Where did the name Merlin come from?
Oddly, Merlin is not in itself a proper name but the name of a city — according to Geoffrey, the magician's place of origin. Merlin, according to Welsh tradition, is not one man but a series of three great magicians bearing one title, including the legendary bard Taliesin, with whom he is identified by Geoffrey.
Merlin the Prophet
Merlin, according to Geoffrey, was born the son of a mortal woman and an incubus, to whom his supernatural powers are attributed. Merlin makes his debut as a prophet when, as a young man, he is kidnapped by the warlord Vortigern. Vortigern had been attempting to build a tower fortress, which tumbled down repeatedly until he is advised by his magicians that it will not stand unless the foundations are sprinkled with the blood of a man who has no human father.
The young Merlin is the obvious choice, but he escapes a gruesome fate by revealing the true cause of the tower's collapse. He tells Vortigern that a pair of dragons are doing battle in a lake under its foundations. These dragons are later revealed to be symbolic of the continual battles between the Britons and the Saxons, which only Arthur is able to calm.
Merlin is not simply an accessory to Arthur but a legend unto himself, appearing in numerous tales of his own. Tales of Merlin's parentage are many and varied — some, such as the medieval telling that Merlin was the son of a nun's congress with a demon, are quite ridiculous. Invariably, however, it is understood of Merlin's parentage that he has no human father. It is the wise Merlin who engineers Arthur's birth, bringing Britain a savior.
The Fall of Merlin
Merlin's downfall, like Arthur's, is due to a woman. Unlike Arthur's tale, Merlin's seems more typically medieval, the great man brought down by the scheming wiles of the evil sorceress to whom he has entrusted his deepest secrets. While Morgan and Guinevere appear to be diluted goddesses, Merlin's scheming lover Nimue embodies every medieval superstition about the evil nature of women. Nimue is described as a beautiful but cruel girl who entreats the elder Merlin to teach her his magic; the magician, quite besotted, agrees against his better judgment to do so. Nimue turns out to be quite ungrateful for Merlin's lessons. At the first opportunity, she uses her newfound skills to destroy him, binding him for eternity in a tower of glass or in the interior of an oak. Strangely, these are both clear symbols of the pagan Otherworld.