Ambrosius Aurelianus
Scholars such as Leon Fleuriot identified Ambrosius Aurelianus with the aforementioned Riothamus figure from Jordanes, an idea which forms part of Fleuriot's hypothesis about the origins of the Arthurian legend. Others, such as Geoffrey Ashe, disagree, since Ambrosius is not called "king" until the somewhat-legendary "Historia Brittonum".