Every now and then someone joins Geni, and begins to argue that Merlin was a real person. This article about the origin of the Merlin legend might be interesting.
The Legendary Origins of Merlin the Magician
"Most people today have heard of Merlin the Magician, as his name has been popularized over the centuries and his story has been dramatized in numerous novels, films, and television programs. The powerful wizard is depicted with many magical powers, including the power of shapeshifting and is well-known in mythology as a tutor and mentor to the legendary King Arthur, ultimately guiding him towards becoming the king of Camelot. While these general tales are well-known, Merlin’s initial appearances were only somewhat linked to Arthur. It took many decades of adaptations before Merlin became the wizard of Arthurian legend he is known as today. - See more at: http://www.ancient-origins.net/myths-legends-europe/legendary-origi...