Merlin is surrounded by other literary characters from a Celtic mythological background or Arthurian legend. The best known are the Blaise scribe who records his story, the King Arthur whom he watches and protects, and the fairy Viviane he loves. Morgane and Viviane are his pupils.

Merlin, commonly referred to as Merlin the Enchanter, is a legendary figure, magician prophet endowed with metamorphosis, commander of natural elements and animals in medieval literature.