The Arthur found in Nennius is not a king, but is called dux bellorum, meaning “duke of war”, or “war-leader”. After the reign of Vortigern, Nennius says,
the Saxons were thriving and increasing in multitudes in Britain.
Their leader was Octa (though it is not clear if Octa still holds his position during the wars with Arthur). Arthur appears out of nowhere, leads the British kings in combat, and enjoys twelve victories against the Saxons and nine different locations: the River Glein, the River Dubglas (four battles here), the River Bassas, the Forest of Celidon, the Castle Guinnion, the City of the Legion, the River Tribuit, Mount Agned (or Breguion), and Badon Hill.
Celidon is the Caledonian Forest in Scotland (Arthur may have been fighting Pictish allies of the Saxons rather than the Saxons themselves), and the City of the Legion is probably Chester. None of the other locations can be identified with any certainty, though many different possibilites have been suggested for each one. Proponents of Arthur as a northern hero locate all of them at northern localities, while other theorists manage to place them in Wales, or Cornwall.
The best possibilities for each battle site – Badon at Bath or Badbury Rings, Glein at Glen in Lincolnshire, Agned at Edinburgh, and so on – are all over the British map, leading some scholars to conclude that the battles were fought by different warriors and were later attributed to Arthur as his fame grew. (Others have used this distances as evidence that Artur had revived the cavalry in Britain.) This theory is feasible, but it should be noted that Nennius does not supply a time frame for the twelve battles. We could easily assume that these battles represent a ten or twenty-year career for Arthur, in which case the distances seem less daunting. Another theory holds that the British forces at each battle called themselves “Arthur’s Men”, confusing later authors into believing that Arthur himself was present.
There is no certainty that ony of the battles were originally associated with Arthur. They are listed as follows.
| 1 | At the mouth of the River Glein There are two English rivers called Glein, either of which might be the site. |
| 2, 3, 4 and 5 | The River Douglas in Linnius K.H. Jackson thinks Linnius (Linnuis) might be Lindsey. See River Douglas. |
| 6 | On the River Bassus Location unknown. |
| 7 | At Cat Coit Celidon In the north, the region called Silva Caledoniae (Wood of Scotland) in Latin. See Cat Coit Celidon |
| 8 | At Guinnion A fortress. Location unknown. See Guinnon. |
| 9 | At the City of Legion Identified as Chester (called Urbs Legionis in Latin). See City of the Legion. |
| 10 | At the River Tribuit Location possibly in Scotland. See Tribuit. |
| 11 | At Mount Agned K.H. Jackson suggests High Rochester for this. In one tenth-century manuscript it is called Breguion, but there may be confusion here with a victory ascribed elsewhere to Urien of Rheged. See Mount Agned. |
| 12 | Badon Either a hill or a mountain. See Badon. |
See also
Topography and Local Legends | The Legend of King Arthur