Merlin

Merlin is the familiar form of the Welsh Myrddin, shaped by medieval Latin and French storytelling. Its deeper origin is probably connected with the old place name behind Carmarthen, with elements referring to the sea and a fort. That makes sea fortress a plausible traditional interpretation, though the journey from place name to personal name is not entirely certain.

Geoffrey of Monmouth helped establish Merlin in twelfth-century literature, and later Arthurian stories made him the celebrated magician and adviser associated with King Arthur. The name's strongest identity is therefore literary and legendary. Myrddin keeps the Welsh form visible, while Merlin is the version recognized across many retellings of the Arthurian world.