Battle of Mons Badonicus - Location and Date: Uncertain

Location and Date: Uncertain

The earliest source to describe the Battle of Mons Badonicus is De Excidio et Conquestu Britanniae (On the Ruin and Conquest of Britain), written by the monk Gildas in the mid 6th century. Gildas writes the battle resulted in 'the last great slaughter' of the Anglo-Saxon invaders by the Britons after a period of violent warfare. According to Gildas, the consequences of Badon had been to halt Anglo-Saxon expansion up to the time of his writing, but the battle and its aftermath had not restored the Britons to their earlier prominence.

Gildas appears to say that the battle ("obsessio"—a siege) occurred in the year of his birth, forty-four years before his time of writing. This would place the battle sometime in the late 5th or early 6th century. However, he does not appear to give the names of the leaders, or offer any information about the location, the course of the battle, or its tactical victors. This reticence was characteristic of Gildas's history in general. Later medieval writers often associated the battle with the legendary King Arthur (see also, "Historical basis for King Arthur"); however, no text decisively dated before the 9th-century Historia Britonnum mentions Arthur in relation to the battle.

Some modern scholars suggest that Gildas' text implies that Aurelius Ambrosius was the Briton leader at Badon. Chapter 25 describes Aurelius as leading the Britons in their early skirmishes against the Saxons. Modern editions of Gildas include a space between this chapter and the next, which mentions Mons Badonicus; this has been interpreted as implying that time had passed between Aurelius and the final victory at Mons Badonicus. However, the space does not appear in the manuscripts; without it, the two sections can be read as implying that the victory at Badon was part of Aurelius' campaigns.