The battle leader, or dux bellorum, of the British in their struggle against the Anglo-Saxons. He was the leader who succeeded Vortigern (and may have been responsible for ousting him from power) and immediately preceded Arthur. It is odd that he is mentioned by the sixth-century historian Gildas, then in the eighth century by Nennius, but by no other historian until the Middle Ages. He nevertheless existed. Gildas describes him as a modest man, which is a surprising quality in a battle leader.

He appears to have been a Celtic nobleman and it has been suggested that the “Ambros” place-names may represent the stations of the units that he raised and led, styled Ambrosiaci. This is an attractive idea, but it is unclear how Amberley, deep in West Sussex and very close to the south Saxon heartland, could possibly have functioned as such a base for Celtic troops.

The Latinized form, Ambrosius, of the Celtic name Ambros or Emrys may have been given by a chronicler, or adopted by Emrys himself as a badge of formal respectability, something that many other British noblemen did. It does not prove, as some have proposed, that he was a member of a Roman family who stayed on after the Roman troops left. He represents a class of post-Roman native British aristocrats who clung to an older order of things and disapproved of Vortigern’s reckless politicking with the untrustworthy Germanic colonists.

It is likely that Ambrosius was a focus for dissent among the Britons over the way Vortigern was leading the confederation to disaster.

Gildas describes how Ambrosius’ leadership marked the beginning of a more successful phase for the British:

When the cruel plunderers [the Saxons attacking the British in about 460] had gone back to their settlements, God gave strength to the survivors [the British]. Wretched people flocked to them from all directions, as eagerly as bees when a storm threatens, begging burdening heaven with unnumbered prayers that they should not be destroyed. Their leader was Ambrosius Aurelianus, a gentleman who, perhaps alone of the Romanized Britons, had survived the shock of this great storm [the Saxon invasion of Britain]; certainly his parents, who may have worn the purple, were slain in it. Under him our people regained their strength and challenged the victors to battle.

After this the British started to win battles, and they were eventually rewarded with the overwhelming victory at Badon.

Another view of Ambrosius comes from Nennius’ Miscellany. There Ambrosius is “the great king among all the kings of the British nation.” This may mean only that his reputation grew steadily after his death, that he was promoted by history, rather as Arthur would be a little later. It may alternatively be a genuine reflection of Ambrosius’ status as dux bellorum.

Interestingly Cynan of Powys was later to be called Aurelianus, which may have been another title of the dux bellorum.

Although it is not known where Ambrosius came from or where he lived, Amesbury in Wiltshire is possible. Amesbury was spelt “Ambresbyrig” in a charter dated 880 and may derive its name directly from Ambrosius himself. If he held Salisbury Plain as his estate, or at any rate this part of it, he would have controlled the critical north-eastern corner of Dumnonia. The frontier of Dumnonia was marked by an earthwork called the Wansdyke, and it lies 7 miles (12km) north-east of Amesbury. Where Ambrosius’ stronghold was is not known, but it may have been the Iron Age hillfort known as Vespasian’s Camp, just 1 mile (1.6km) to the east of Stonehenge. This spacious fort would have made an excellent rallying-point for the forces Ambrosius gathered; it would also make sense of the otherwise inexplicable association that Geoffrey of Monmouth made between Ambrosius and Stonehenge.

From about 460 Ambrosius is said to have organized an island-wide resistance of the British to the Anglo-Saxon invasion. His campaign prospered. The Anglo-Saxon Chronicle is silent about this period, suggesting that the British were in the ascendancy; there is no boasting of a Saxon victory until 473. Gildas enthused about Ambrosius: “though brave on foot, he was braver still on horseback.” This implies a preference for cavalry action, which his successor, Arthur, would share. “The Britons fled to him like swarms of bees who fear a coming storm. They fought the war with Ambrosius as their leader.”

Fanciful legends were later embroidered round this heroic figure. It was said that in Ambrosius’ reign Merlin the magician brought the stones of Stonehenge over from Ireland and set them up in Wiltshire. This does not square with the geology or archeology of Stonehenge. The sarsen stones came from the chalk downs near Avebury; the bluestones came from Pembrokeshire. Both arrived on Salisbury Plain in the middle of the third millennium BC—and that was long, long before the time of Ambrosius Aurelianus.


At Badon, a great battle took place in which the British won a major victory over the Saxons. It was Arthur’s first recorded battle in the year 516. Its outcome was so decisive that it held back the Saxons for several decades, and it was largely due to Arthur’s exploits during this battle that he owes his reputation as a great warrior.

Several locations for Badon have been proposed, but there are early references to the city of Bath in which the name is spelt Badon—for example, in The Wonders of Britain, Nennius refers to “the hot lake where the baths of Badon are”—and so the likeliest battle site by far is Little Solsbury Hill, about 2 miles (3km) north-east of Bath. This was on the eastern frontier of Dumnonia, at the point where the old Roman road, Fosse Way, came down the eastern valley-side from Banner Down toward a crossing-place on the Avon River at Bath. In the sixth century this was a key location, right on the frontier between Celt and Saxon, and would have been a natural access point to the Celtic kingdom for an advancing Saxon army. Little Solsbury Hill, which had a small fort on its summit, was an obvious vantage point from which the British warriors could have watched the invaders approaching from the east or north-east and then descended to attack as they passed below. The Saxons would have been caught between the steep valley side and the river.

In the annals there is a strange description of Arthur carrying a cross on his shoulders. This may be explained by the misreading of the word for “shoulder.” The Old Welsh for “shoulder,” scuid, is very similar to the Old Welsh word for “shield,” scuit. Scribes regularly read whole phrases from the documents they were copying and muttered them to themselves as they wrote. It was easy to make mistakes, especially when words both looked and sounded similar to other words. So the original description may have read, “Arthur carried the cross of our lord Jesus Christ on his shield.” The image of the cross could easily have been painted onto the shield, or designed into the shield’s metalwork, or embroidered into a fabric covering for the shield. It may be significant that high-ranking officers in the late Roman army frequently carried portraits of emperors on their shields. It would be quite logical for a Christian British commander-in-chief educated in the late Roman tradition to carry an emblem of Christ: after all, he recognized no earthly overlord.

The hammering of the Saxons in the Battle of Badon brought about a major change. For a couple of decades the western frontier of the Saxon world was fixed.


A very imposing Iron Age fort on the summit plateau of a free-standing hill. The ancient fortifications are mostly tree-covered now, but the four earth ramparts are still impressive. Although often described as an Iron Age fort, Cadbury began earlier, in the Bronze Age. In the Iron Age it became a major focus for the Durotriges tribe. During the Roman occupation, the Britons were forcibly removed after a revolt in AD 61, and the site returned to agriculture.

The site was reoccupied in the fifth–sixth centuries, when the advance of Saxon settlers prompted local Britons to use it as a refuge again. Ambrosius Aurelianus lived at the right time to organize the refortification of Cadbury in around 470. Buildings were added, including a substantial Dark Age hall. The strategic position of Cadbury near the eastern frontier of Dumnonia and its huge area make it a likely muster-point for warriors assembling to do battle with the Saxons in the period 500–70.

The history of this magnificent hillfort is long and complicated, but it was a center of Celtic resistance to invaders at least three times: in the rebellion against Rome in 61, in the Badon campaign against the Saxons in 500–20, and in the Dyrham campaign in the years around 570.

In 1532, John Leland visited the site, observing:

At South Cadbyri standith Camallate, sumtyme a famose toun or castelle, apon a very torre or hill, wunderfully enstrengthenid of nature… The people can tell nothing ther but they have heard say that Arture much resorted to Camalat.