Merlin first appears in Geoffrey of Monmouth's 'Historia Regum Britanniae', establishing the character as a legendary figure in British folklore and literature.
Merlin becomes a central figure in Arthurian legends through medieval romances, notably in works by authors like Chrétien de Troyes and Thomas Malory.
Merlin is popularized in modern literature by T.H. White's 20th century work, which presents him as an eccentric and wise mentor.
The character Merlin is widely depicted in various films and TV series, including the BBC series 'Merlin' (2008-2012), bringing him to a broad modern audience.