Naked, hairy wild man of the woods who demonstrates prophetic powers at the court of Rhydderch Hael in Strathclyde, the 6th-century Welsh-speaking kingdom of the Old North, i.e. the Scottish Lowlands. By critical consensus, much of the legend of Lailoken's life contributes to Geoffrey of Monmouth's conception of Merlin in the Vita Merlini (c.1149). In the 15th-century Scottish story known as ‘Lailoken and Kentigern’, the hairy wild man confesses to St Kentigern that he is the cause of the deaths of those who perished at the battle of Arfderydd (573/575). Myrddin (Merlin) is recorded as having gone mad after this defeat.
See H. D. L. Ward, ‘Lailoken (or Merlin Silvester)’, Romania, 22 (1893), 504–26;‘Lailoken and Kentigern’ is translated, 514–525.Kenneth H. Jackson, Béaloideas, 8 (1938), 48–9;James Carney, Studies in Irish Literature and History (Dublin, 1955), 129–53;Basil Clarke, Life of Merlin (Cardiff, 1972).