Merlin

Merlin is best known as the wizard featured in Arthurian legend. The standard depiction of the character first appears in Geoffrey of Monmouth's Historia Regum Britanniae, and is based on an amalgamation of previous historical and legendary figures. Geoffrey combined existing stories of Myrddin Wyllt (Merlinus Caledonensis), a northern madman with no connection to King Arthur, with tales of Aurelius Ambrosius to form the figure he called Merlin Ambrosius.

Geoffrey's version of the character was immediately popular, and later writers expanded the account to produce a fuller image of the wizard. His traditional biography has him born the son of an incubus and a mortal woman who inherits his powers from his strange birth. He grows up to be a sage and engineers the birth of Arthur through magic. Later Merlin serves as the king's advisor until he is bewitched and imprisoned by the Lady of the Lake.