by Brian Edward Rise
The Scottish forest that is the location of Arthur's seventh battle in the Historia Brittonum by Nennius where Arthur fought the Picts and the Angles. Also known as Cat Coit Celidon, this is the modern day Caledonian Wood which at one time covered most of Selkirkshire and Dumfries and ran over the highlands around the upper Clyde and Tweed rivers.
A problem arises because the northern Angles did not appear within a credible time-frame for Arthur. Perhaps he was battling Picts as part of some kind of alliance for, around the middle of the fifth century CE, there was an Anglo-Pictish alliance mentioned by Bede in the Historia Ecclesiastica. However, there is no mention of one at the time of Arthur's other relevant dates. This early date placement for Arthur presents chronological problems with the battles of Badon and Camlann (both of which have their own sets of dating problems) which both Gildas's De Excidio Britanniae and the Annales Cambriae place fifty years later.
Celidon is also the location of the mad, prophetic wanderings of Lailoken, the "Wild Man of the Woods," driven insane by the Battle of Arfderydd in Cumbria circa 575 CE. Known in the Welsh tradition as Myrddin, he wanders these woods for fifty years in poems like Afallennau ("Apple Trees"). This Myrddin was the prototype for Merlin in Geoffrey of Monmouth. This is why Merlin is believed to be buried at Drumelzier, on the upper Tweed river.