The Magi were a priestly caste dominant in ancient Persia; Zoroaster (circa 660BC-circa 580BC) may have been one. Certainly the religious beliefs of the Magi, as far as they are known, have marked similarities to Zoroastrianism: there is a conflict between Good and Evil, with Good ultimately triumphant; and there is some anticipation of a Messiah. The wise men in the Bible who anticipate the coming of Christ are referred to as the Three Magi.
Over the centuries since, the term has gradually accreted a constellation of associations, as evidenced by the range of figures, both real and fictional, who have been called magi: Moses, Solomon, Virgil, Pythagoras, Simon Magus, Theophilus of Adana, Apollonius of Tyana, Merlin, Roger Bacon, Cagliostro, Prospero, Saint-Germain, Faust, John Dee, Sarastro, etc. A magus is likely to be male, elderly, wise, powerful and manipulative. He may stand as a Liminal Being between the young man or woman and a goal, which may be maturity (> Rite of Passage; Godgame), or wisdom or a kingdom. But, because he is dedicated to the gaining of knowledge, to the penetrating of arcana which may be forbidden, he may be dangerous; he may be a Secret Master; he may be the head of an order or caste, either openly or in secret (> Pariah Elite); he may or may not be capable of Magic, but that ability will be secondary to his magus-hood.
Fantasy tales in which magi appear include Peter Ackroyd's The House of Doctor Dee (1993) and other novels about John Dee, Peter S Beagle's The Innkeeper's Song (1993), which features a magus who (as Schmendrick in The Last Unicorn ) was a wizard in earlier life, M John Harrison's The Course of the Heart (1992), E T A Hoffmann's The Golden Pot (1814), William Kotzwinkle's Fata Morgana (1977), Amanda Prantera's The Cabalist (1985), Herbert Rosendorfer's The Architect of Ruins (1969) and of course William Shakespeare's The Tempest (written circa 1611; 1623) and John Fowles's The Magus (1965). [JC]