Nennius (c. 769-??) was a Welsh historian and monk in the order of St. Elfodd. It could also be argued that Nennius was an author of historical fiction and a geographer of post-Roman Britain. He's believed to have lived in the area made up by present day Brecknockshire and Radnorshire counties in Powys,Wales. He's largely credited today for having authored the original manuscript of the Historia Brittonum, which gives a semi-factual account of early British history beginning with Celtic and Rom… (More on Nennius)