(In Welsh: Emrys or Myrddin, latinized as Merlinus)

   In the traditional legend, Merlin was Arthur's magician and counselor, in many ways the architect of his reign.
Geoffrey of Monmouth was the first to connect Merlin with Arthur. In his Historia Regum Britanniae and the Vita Merlini (Life of Merlin), Merlin has little direct contact with Arthur, working in the background with his predecessors toward his kingship. It is only in the medieval Romances that Merlin achieves prominence as court magician to King Arthur, and only later in modern novels, that he becomes Arthur’s tutor. During the middle ages, his glamour outshown Arthur. 

   His life was in three phases: innocent prophetic youth, madman and hermit/ wise elder. It was Geoffrey of Monmouth whose Historia Regnum Brittaniae and Vita Merlini provide the chief early sources for his life. In these books, Merlin makes a series of prophecies concerning the fate of Britain.
   In the classic form of the tale, Merlin was begotten by an incubus. Robert de Boron says the devils of Hell had determined to set on earth an evil being to counterbalance the good introduced by Jesus Christ. Happily, the child was promptly baptized countering the evil and giving us our magician! At the time of Merlin's youth, Vortigern, King of Britain, retreating from the treachery of his Saxon allies and the arrival of his British enemies, Ambrosius Aurelianus and Uther Pendragon, determined to build a tower at Dinas Emrys near Mount Snowdonia in Wales. His engineers' attempts proved futile for each day's labors were lost as the tower collapsed without apparent reason during the night. The king's counselors told him he would need to sacrifice a fatherless child to remedy this. A search turned up Merlin Emrys. The youth confounded the king's advisors and prophesied that the real reason for the tower's collapse was the existence of a pool beneath the foundations. Digging revealed the truth of this and a brace of dragons emerged, one red and one white; which caused Merlin to utter a series of prophecies about Vortigern's death and the future of the land.
   From this point, he becomes increasingly involved in the struggle that was to have its peak with the reign of Arthur. When Aurelius Ambrosius defeats Vortigern, he wished to put up a monument of the men killed treacherously by the Saxons during the 'Night of the Long Knives'. Merlin advised him to procure certain magical sarsen stones from Ireland and these were erected on Salisbury Plain as Stonehenge (historically inaccurate as Stonehenge was built over a thousand years before the time, but may show an attachment between the great henge monument and the name Myrddin, since Britain was known as Clas Myrddin or Merlin's Enclosure). After the death of Aurelius, when Uther came to the throne, Merlin arranged for him to seduce Igraine by magically having him take the shape of her husband, Gorlois. He took the child, Arthur, born of this union, and spirited him away for safety. When the aged and infirm Uther is nearing his last battle, Merlin arranges the Sword-in-the-Stone contest, and magically or pre-ordained, Arthur draws forth the sword and becomes the true and rightful king. Merlin becomes Arthur's main counselor  and architect of the Round Table but slowly withdraws from the court.
   According to Malory in the Morte D'Arthur, Merlin became infatuated by Nimue (elsewhere called Viviane), whom he taught magical secrets which she used to imprison him in a glass tower, or under a stone or in a hawthorn tree. Geoffrey, however, has him active after Camlann, bringing the wounded Arthur to Avalon.

   "After making the predictions of the Prophetiae Merlini, Merlin’s next task in the Historia Regum Britanniae was to assist Ambrosius in erecting a monument to the Briton leaders treacherously slain by Hengist at the Cloister of Ambrius. Merlin proposed that Ambrosius send his brother Utherpendragon to arrange the relocation of Stonehenge from Ireland to Britannia. Merlin’s proposal reflects a genuine folk memory of the ancient transportation of certain of the Stonehenge monoliths, the so-called bluestones, from the Prescely mountains in southwest Wales (near Moridunum or Caer Myrddin) to the Amesbury area for the worship of the god Myrddin. In Ambrosius’s day, southwest Wales was the Irish kingdom of Demetia; it was thus correctly described as “Ireland,” or, more precisely, “land of the Irish.” Geoffrey has confused the true story of Stonehenge and its patron deity Myrddin with an expedition to the Irish-ruled part of Wales by Ambrosius’s general, whom Geoffrey calls Utherpendragon. Geoffrey’s source must have said something to the effect that “Utherpendragon led an army into the land of the Irish, whence came Myrddin’s stones at Stonehenge.” Geoffrey misconstrued this statement as a reference to an invasion of Ireland and a concurrent movement of the monoliths by Merlin. In fact, Geoffrey’s source meant that Utherpendragon led an expedition into Demetia, which was then ruled by the Irish, and that it was from Demetia that certain of the monoliths at Stonehenge had been taken in ancient days. Geoffrey exploits his character of Merlin at this point to explain how Utherpendragon was able to transport the Stonehenge bluestones from Ireland to Britannia. Geoffrey had, of course, overestimated the distance over which the stones had to travel. He also underestimated the skill and ingenuity of his ancestors. Geoffrey therefore seized upon his mistaken association of the bard Myrddin with the Magister Militum Ambrosius for an answer to the mystery: Merlin’s magical arts could suffice when the brute strength of Utherpendragon’s soldiers would prove unavailing. Merlin thus became a sort of deus ex machina (“god by machine,” a reference to the theatrical device by which supernatural beings were made to appear to fly on stage), or perhaps more accurately magus ex machina (“magician by machine”), to account for events in history which were incomprehensible to the medieval understanding. Merlin was such a convenient device for explaining enigmatic elements in Arthurian history that the Romancers readily followed Geoffrey’s lead, making the poet-turned-sorcerer into a leading (some would say the leading) character in Arthurian literature."
        Excerpt from The REAL King Arthur, A History of Post-Roman Britannia, A.D. 410 - A.D. 593, available for $29.95 (incl p&h) from SKS Publishing Co., P.O. Box 101038, Anchorage, Ak 99510-1038

   It is possible that Geoffrey's Merlin may be a merging of extant stories of Arthur's counselor and the sixth-century Welsh poet, Myrddin ab Morvryn, often called Merlin Sylvester or Merlin Calendonensis (several ancient poems are attributed to him, including Affalenau). Myrddin was the court poet of Gwenddolau ab Ceidio, a pagan king whose court was located just north of Hadrian's wall near Carlisle, and fought at his side at the Battle of Arderydd (Arthuret) in 573CE. Myrddin was driven mad when his king was killed in the battle.
   Myrddin's madness is paralleled in several traditional stories concerning the Irish Suibhne Gelt and the madman from the life of Saint Kentigern, Lailoken
(Vita Kentigerni is believed to have been written by Herbert, Bishop of Glasgow from 1147 to 1164). All three mad prophets are said to suffer the threefold death caused by falling, hanging and drowning, a druidic style ritual death.
   As mentioned above, he went mad after the battle of Arthuret and became a wild man, living in the woods. According to Giraldus Cambrensis, this was because of some horrible sight he beheld during the fighting, where three of his brothers were killed. King Rhydderch Hael was married to Merlin's sister, Ganieda, who persuaded him to give up his life in the forest, but he revealed to Rhydderch that she had been unfaithful to him. He decided to return to the greenwood and urged his wife, Guendoloena, to remarry. However, his madness once again took hold of him and he turned up at the wedding, riding a stag and leading a herd of deer. In his rage, he tore the antlers from the stag and flung them at the bridgegroom, killing him. He went back to the woods and Ganieda built him an observatory from which he could study the stars. Welsh poetry antedating Geoffrey largely agrees with this account, though it has Merlin fighting against Rhydderch rather than for him. Similar tales are told about a character called Lailoken, who was in Rhydderch's service and this may have prompted Geoffrey to change the side which Merlin was on.
   As to the historical Merlin, if he existed, modern writers such as Ward Rutherford and Nikolai Tolstoy think he may have been a latter-day Druid and so took part in shamanistic practices. Jung and von Franz also see shamanistic elements in the story of Merlin. This contrasts with the earlier theory of E. Davies that Merlin was a god (the evening star), and his sister Ganieda a goddess (the morning star). Geoffrey Ashe would connect him with the cult of the god Mabon. Because of his association with stags, there may be a connection with Cernunnos, the Celtic horned god.
   Merlin's mother was called Aldan in Welsh tradition. The Elizabethan play The Birth Of Merlin - which may have been partially authored by Shakespeare calls her Joan Go-to-'t. That he had no father does not seem to be a feature of Welsh tradition in which he is given the following pedigree: Coel Godebog - Ceneu - Mor - Morydd - Madog Morfryn - Myrddin (Merlin). He was also said to be the son of Morgan Frych who, some claimed, was a prince of Gwynedd. Both Welsh poetry and Geoffrey have him speaking with Taliesin, with whom he seemed to be considerably connected in the Welsh mind. Thus one Welsh tradition asserted he first appeared in Vortigern's time, then was reincarnated as Taliesin and reincarnated once more as Merlin the wild man. The idea that there were two Merlins, wizard and wild man, is found in Giraldus Cambrensis (the Norman-Welsh chronicler of the twelfth century), doubtless because of the impossibly long lifespan assigned to him by Geoffrey of Monmouth. A modern relic of the Merlin legend was to be found in the pilgrimages made to Merlin's Spring at Barenton in Brittany, but these were stopped by the Vatican in 1853.

Merlin in Malory's le Morte