While some of the Arthurian battle sites as I have identified them must be considered problematic or even doubtful, there is no denying that when they are plotted out on a map (see above) they stretch from south to north in a fairly well-defined line. Many center on the Roman Dere Street, which must be considered a sort of boundary or frontier zone between the Britons and their enemy, the Germanic invaders.
A battle at Camboglanna does indeed look like an internal conflict, and the tradition which records Medrawt/Moderatus as Arthur’s opponent may, in fact, be correct.
To summarize, I include here Alan James’ opinion of my Arthurian battle map, found at the beginning of this book:
“If you're assuming late 5th century, the archaelogical and (earliest OE) p-n evidence suggests the main concentration of Germanic-speakers would have been around the Humber, with control of York and extending west to the Magnesian Limestone/ Dere Street - i.e. the beginnngs of Deira and Lindsey; smaller but significant settlements along the Tees, and in the Yorkshire Gap, with control of Catterick; likewise along the Tyne and eastern part of Hadrian's Wall. Further north probably still P-Celtic, but there were of course strategic sites on both sides of the Forth; likewise to the west, strategic sites along the Wall and either side of the Solway Firth.
Whether or not Arthur was involved, I can well believe there were battles at all the places you've marked!”