This name was sometimes used as a personal name, and was borne by a few early saints, including a Roman soldier martyred with Nereus in the 1st century.
Geoffrey based parts of Merlin's character on Myrddin Wyllt, a legendary madman and prophet who lived in the Caledonian Forest. Other parts of his life were based on that of the historical 5th-century Romano-British military leader Ambrosius Aurelianus (also known as Emrys Wledig). In Geoffrey's version of the tales and later embellishments Merlin is a magician and counselor for King Arthur.
Other notable bearers include Owain the Great, a 12th-century king of Gwynedd, and Owain Glyndwr, a 14th-century leader of the Welsh resistance to English rule.