The following list of legendary kings of Britain derives predominantly from Geoffrey of Monmouth's circa 1136 work Historia Regum Britanniae ("the History of the Kings of Britain"). Geoffrey constructed a largely fictional history for the Britons (ancestors of the Welsh, the Cornish and the Bretons), partly based on the work of earlier medieval historians like Gildas, Nennius and Bede, partly from Welsh genealogies and saints' lives, partly from sources now lost and unidentifiable, and partly from his own imagination (see bibliography). Several of his kings are based on genuine historical figures, but appear in unhistorical narratives. A number of Middle Welsh versions of Geoffrey's Historia exist. All post-date Geoffrey's text, but may give us some insight into any native traditions Geoffrey may have drawn on.