Cináed mac Ailpín (Modern Gaelic: Coinneach mac Ailpein), commonly Anglicised as Kenneth MacAlpin and known in most modern regnal lists as Kenneth I (died 13 February 858) was king of the Picts and, according to national myth, first king of Scots, earning him the posthumous nickname of An Ferbasach, "The Conqueror". Kenneth's undisputed legacy was to produce a dynasty of rulers who claimed descent from him and was the founder of the dynasty which ruled Scotland for much of the medieval period. The Kenneth of myth, conqueror of the Picts and founder of the Kingdom of Alba, was born in the centuries after the real Kenneth died.
When humanist scholar George Buchanan wrote his history Rerum Scoticarum Historia in the 1570s, a great deal of lurid detail had been added to the story. Buchanan included an account of how Kenneth's father had been murdered by the Picts, and a detailed, and entirely unsupported, account of how Kenneth avenged him and conquered the Picts. Buchanan was not as credulous as many, and he did not include the tale of MacAlpin's treason, a story from Giraldus Cambrensis, who reused a tale of Saxon treachery at a feast in Geoffrey of Monmouth's inventive Historia Regum Britanniae.