Merlin

Merlin is the great magician of Arthurian legend, and his literary origins are as layered as Arthur's own. He emerges from the Welsh figure of Myrddin, a wild prophet-poet, and from Geoffrey of Monmouth's twelfth-century histories, where he is a fatherless boy of prophetic power, before the French romances made him the wizard-counsellor of the whole Arthurian world.

In the developed legend he is born of a mortal woman and an otherworldly (in some tellings, demonic) father, from which he derives his uncanny powers, turned to good ends. He engineers Arthur's very conception, arranges the test of the sword in the stone that reveals the rightful king, establishes the Round Table, and serves as the shaping hand behind the young king's reign, prophet, shape-shifter, and maker of kings. His end is a fall through his own art: enchanted by the enchantress (Nimue or Viviane) to whom he has taught his magic, he is imprisoned forever in a cave, a tree, or a tower of air. Merlin embodies a recurring theme, the power of knowledge and prophecy, and its insufficiency to save even the knower from fate.

Merlin as he is known today is a literary composite rather than the record of one figure. Geoffrey of Monmouth, who introduced him to wide readership in the twelfth century, appears to have fused a Welsh tradition of a wild prophetic madman named Myrddin Wyllt, said to have gone insane after a battle and lived as a hermit uttering prophecies in the forest, with a separate earlier figure, Ambrosius Aurelianus, a shadowy post-Roman British leader mentioned in older sources. Geoffrey renamed his combined figure Merlinus, likely to avoid an unfortunate resemblance between Myrddin and a Latin obscenity, and gave him the role of prophet and enchanter attached to Arthur's court that has stuck ever since.

Later medieval writers kept building on this base rather than drawing on any single stable source: Robert de Boron added the account of Merlin's demonic parentage and his role in arranging Arthur's conception and the Round Table, and Thomas Malory's fifteenth century synthesis combined these accretions into the version most modern retellings still follow. The result is a figure assembled in layers across several centuries and several independent literary traditions, Welsh prophetic legend, Galfridian pseudo-history, French romance invention, with no single original Merlin behind them that scholarship can point to and call the source.