Anglicized form of Welsh 'Myrddin' meaning 'sea fortress'; the legendary wizard of Arthurian tales.
Merlin is an Anglicization of the Welsh Myrddin, a name rooted in the Brythonic place name Moridunum — the Roman settlement now known as Carmarthen in Wales, whose name likely meant "sea fort" or "sea hill." The historical figure of Myrddin appears in early Welsh poetry as a prophetic, possibly mad, figure wandering the northern British wilderness. It was Geoffrey of Monmouth who, in his 12th-century Historia Regum Britanniae and the subsequent Vita Merlini, transformed Myrddin into Merlin and wove him into the Arthurian cycle as the archetypal wizard, counselor to kings, and master of transformation.
In Geoffrey's telling, Merlin orchestrates the very conception of King Arthur, establishing himself as the hidden hand behind civilization. S. H.
White's The Sword in the Stone, and countless others. The name has consequently carried an aura of wisdom, mystery, and benevolent power for nearly a millennium. As a given name, Merlin has never been widely common, which preserves its distinctiveness; it sits outside fashion's tides, feeling simultaneously ancient and gently unusual. Parents drawn to mythology, magic, or Arthurian legend find in Merlin a name with extraordinary cultural depth.