Nennius. Author of the Historia Brittonum, c. ad 800, a principal source for the post-Roman period. Much of the Historia attributed to Nennius has been described as having ‘all the historical reliability of fairy-stories’. Nennius' reference to Arthur may well fall into this category. However, Nennius also included some short passages derived from reputable earlier authors, such as Constantius of Lyons on St Germanus. Nennius himself wrote in his preface: ‘coacervavi omne quod inveni’ (‘I have made a heap of everything I have found’). The result of Nennius' efforts is a well-intentioned but sometimes bizarre account of Britain in the 5th and 6th cents. which cannot be relied upon, although some scholars argue that Nennius preserved useful titbits of information.

Eleanor Scott

Nennius (fl. c.800), Welsh chronicler. He is traditionally credited with the compilation or revision of the Historia Britonum, which includes one of the earliest known accounts of King Arthur.