In the legends about King Arthur, the king had the help and advice of a powerful wizard named Merlin. Indeed this magician, who arranged for Arthur's birth and for many aspects of his life, can be seen as the guiding force behind the Arthurian legends*. Many stories about Merlin circulated in medieval times.
medieval relating to the Middle Ages ¡n Europe, a period from about A . D . 500 to 1500
Origins and Sources. The figure of Merlin seems to be based on a magician named Myrddin, who appeared in the pre-Christian mythology of the Celtic* peoples. The writings of Nennius, a Welsh storyteller of about A . D . 800, include tales of a young magician named Ambrosius who became an adviser to Vortigern, a legendary king of early Britain.
* See Names and Places at the end of this volume for further information.
Some 300 years later, the British chronicler Geoffrey of Monmouth told a more elaborate story about the magician in his History of the Kings of Britain (1136). In this account, a sorcerer known as Merlin Ambrosius served as adviser to British king Uther Pendragon and, later, to his son Arthur. Geoffrey of Monmouth also wrote a work about Merlin that drew on old Celtic legends about a "wild man of the woods" with magical and fortune-telling powers.
Other entries related to Merlin are listed at the end of this article.
Some early legends claimed that Merlin was the son of a demon and of a human woman. Only half human, Merlin was mysterious and unpredictable, sometimes helping the human race but sometimes changing his shape and passing long periods as a bird, a cloud, or something else. He also desired and seduced women. By the 1200s, however, the influence of Christianity was reshaping the Arthurian legends, and Merlin became a more respectable figure—a wise old man who supplied moral guidance as well as magic.
Merlin's Life and Works. In the legend of Vortigern, the king was trying to build a temple on Salisbury Plain, but it kept falling down. The boy Ambrosius told the king of a vision in which he had seen a red dragon and a white dragon fighting in a pool under the temple's foundation. From this, he predicted that the red dragon of Wales (King Vortigern) would be defeated by the white dragon of Britain (King Uther Pendragon), which later happened. The magician then built the temple himself, using his magic to bring standing stones from Ireland and to arrange them on the plain on a single night. That, according to legend, was how Stonehenge was built.
Merlin Ambrosius became the ally of Uther and used his magic to enable Uther to spend a night with another king's wife. The child born of that union was Arthur. Merlin predicted that he would be a great king who would one day unite all of Britain.
Entrusted with Arthur's upbringing, Merlin prepared the boy for kingship. Some accounts say that the wizard fashioned the magical sword Excalibur that proved that Arthur was the rightful king. According to other stories, Merlin also created the Round Table around which Arthur's knights sat. He was Arthur's helper and adviser in many things. Yet even Merlin could not prevent the final crumbling of the knights' fellowship and the fall of Arthur, as recounted in every version of the Arthurian legends.
As for Merlin's own fate, accounts vary. Some say that he lost his wits after Arthur's defeat and wandered into the woods. Most versions of the magician's story, however, end with his being tricked by a witch named Nimuë (or in some accounts by the Lady of the Lake), with whom he had fallen in love. Nimuë did not really care for Merlin but simply wanted to learn his secrets. When she had learned enough, she trapped him in an underground cave from which he could never escape.