Unique among the territories of the Western Roman Empire in the 5th century, Britain succeeded in holding back and even reversing the tide of Germanic conquest for nearly two centuries. This was an age of heroes... It was the Age of Arthur!

This is the Sixth-part of our discussion of Britain in the so-called Age of Arthur: the 5th though the mid-6th Century A.D. It is a fascinating period, with the Classical civlization of Greece and Rome giving way to the Germanic “Dark Ages”. It was the sunset of Celtic-Roman culture in Britain; it was the Age of Arthur!

But who was Arthur?

Before we answer that question, it is necessary we understand the world in which he lived.

(Read Part Five here; or start from the beginning here!)


As the Saxon terror spread throughout the south of Britain, the first victims were the farmers and villa-owning Romanized gentry of the open country. Unlike town and city dwellers, these had no high, strong walls to shelter behind; nor military garrisons to defend those walls. Farms and villas were pillaged, the inhabitants driven off or killed. Archeological finds show hoards of Roman coins from this period; hastily buried by the owners before fleeing, perhaps in anticipation of one day returning.

As previously stated, many of these fled to Armorica (Brittany), founding a British colony that in time lent its name to the area. Many, but not all: some stayed and fought back. These were led by a Romano-British gentlemen said to have been descended from Roman aristocracy, and to have been a staunch opponent of Vortigern’s Saxon policy.

That man was Ambrosius Aurelianus.

Gildas mentions Ambrosius by name, as leader of the British resistance to the Saxons after the fall of Vortigern from power. Like most of the principles of this age, little of his origin or antecedents are certain. Gildas says his parents (who perished in the Saxon Terror) “wore the purple”.

This has been interpreted as meaning that Ambrosius’ father (or, more likely, grandfather) had been a previous Roman Emperor; perhaps Constantine III, who before being hailed by his troops as Imperator had held the office of Comes Britanniae. Another theory is that Gildas meant to say that Ambrosius’ family was of Senatorial rank; as Roman Senators wore purple-bordered togas or tunics. However, the term “wore the purple” is used repeatedly throughout Roman and Byzantine history exclusively as a synonym for one of imperial rank. I believe Gildas is certainly stating that Ambrosius was descended from a former Emperor or imperial pretender.

It has also been suggested that Ambrosius’ family were true Romans, only recently immigrated to Britain in the late 4th century. An Aurelius Ambrosius, father of St. Ambrose, was Prefect of Gaul in the early 4th century. It is very possible that he was a near ancestor or kinsman of the Ambrosius Aurelianus active in Britain in the 5th century.

His power-base was in the south-central or southwest of Britain; with one very credible theory (1) placing his estates at Amesbury, on the edge of the Salisbury Plain (Stonehenge is associated with both Ambrosius and Arthur in the various legends). An early spelling of Amesbury, near Stonehenge, is Ambrebyrig (Ambrose’s burh, or fortified town); and an ancient Iron Age hill-fort, Vespasian’s Camp, lies only just 2 km to the east. Historian R. Castleden suggests this would have made an excellent stronghold and rallying point for resistance, capable of containing a garrison of up to a thousand soldiers.

As Saxon warbands followed the Thames Valley and the Roman roads westward, burning and murdering as they passed, they would have come into lands owned by Ambrosius’ family.

Tradition has it that his family was slain, and he alone escaped harm (perhaps being in exile in Armorica at the time). But while many fled, Ambrosius (returned?) to organize and lead the resistance.

These same traditions have Ambrosius Aurelianus leading the anti-Vortigern opposition in Britain. He may have been a member of the Romanized aristocracy that resented Vortigern, a tribal strong-man from the west; and his usurpation of authority in Britain. This opposition may have been religious, as well. It should be remembered too that religious conflict, between Catholic and Pelagian Christians, wracked Britain in this period. It has been suggested above that Vortigern was a champion of the Pelagians. As previously discussed, Vortigern may have been the leader of the Pelagian "heretics" in Britain; while the Romanized aristocracy of southern Britain may have been stanchly Catholic/Orthodox.

One theory has Ambrosius rebelling against Vortigern in the 430s; Nennius even mentioning a battle between Ambrosius and a “Guitolinus”/Vitalinus at Wallop, near Ambrosius’ estates at Amesbury.

A battle between Vortigern and Ambrosius in the late 430s raises many questions.

First, was this “Vitalinus” an officer (perhaps relation) of Vortigern? Or is Vitalinus the real name of Vortigern? “Vortigern”, as many scholars believe, being a Brythonic title; meaning “High King”? Interestingly, Geoffrey of Monmouth names Guitolinus as an Archbishop. Again, we see hints that perhaps Vortigern was in fact a title; and that he was in fact this same Guitolinus/Vitalinus. Adhering to the Pelasgian creed, he left the church and became both the leader of Britain as Vortigern (High King) and champion of the Pelagians.

The second question raised is one of chronology. Clearly, an Ambrosius active against Vortigern at this early date cannot be the same man who led the resistance to the Saxons after 460. This suggests two different characters: Ambrosius “the Elder”, a wealthy magnate and member of the Council of Britain, who opposed Vortigern in the 430s; and his son, Ambrosius Aurelianus "the Younger", the later British leader.

Was Ambrosius the Elder secular leader of the Catholic faithful?

Both Nennius (Historia Brittonum, written in the first-half of the 9th century) and Geoffrey of Monmouth (Historia Regum Britanniae, circa 12th century) have Ambrosius Aurelianus fleeing as a boy (the former puts his place of refuge in Wales, the latter in Brittany) from Vortigern’s persecution, following the defeat of his father (at the Battle of Wallop?) and murder of his family. Some recent speculation has suggested that these events were linked to Vortigern’s Saxon policy. However, as the Saxon Advent occurs no sooner than 447 and more likely in 449; this cannot be the case. The strife in the 430s that led to the death of Ambrosius the Elder must have been something else; caused or exacerbated by the underlying religious strife throughout the land.

Château de la Roche Goyon, a famous fortress on the spectacular coast of Brittany. Such naturally strong places were fortified as early as the Iron Age; and afforded refuge for large numbers of aristocratic Britons and their dependents fleeing the disorders in Britain during the 5th century. One of these refugees may have been Ambrosius Aurelianus "the Younger".

In either case, Ambrosius Aurelianus (the Younger?) spent the last decade of Vortigern’s rule in exile. Nennius elaborates, making fear of the exile’s return one of the reasons for Vortigern’s reliance on Saxon mercenaries. Ambrosius was more than an enemy of his regime: he was Vortigern’s personal nemesis, agent of the righteous retribution Vortigern knew was coming!

Now, following the Saxon Terror and the death of Vortimer (see Ch 5), Ambrosius returned (sometime between 456 and 458) to reclaim his ancestral estates; and to organize a national resistance to both Vortigern and the Saxons. According to Gildas, Ambrosius returned to Britain and took command of the Britons, "after a time, when the cruel plunderers had gone home". This occurred, likely, following the retreat of the Saxon’s in the face of Vortimer’s offensive in Kent and Hengist’s temporary retreat from Britain (or onto Thanet) after the fight at Wippedesfleot/Ebbsfleet (456?).

He likely did not return alone; but with a force of Briton exiles, particularly those who were loyal to his father. It is tempting to speculate that with him returned what the Britons (and later Welsh) called a Teulu (“Family”): a household bodyguard unit, known to the late Romans and Byzantines as bucellarii.

Gildas the Monk, writing in the mid-6th century, says of Ambrosius that though “brave on foot, he was braver still on horseback”. If, as Nennius suggests, he returned from exile in Armorica, it is not unlikely that he recruited this bodyguard unit, at least in part, from the best horseman there available: the Sarmatian Alani.

As noted in previous parts of this series, Alan horsemen had been settled in Armorica during this period by Flavius Aetius. The long history of the Alani is one of joining forces with neighboring peoples: first the Goths in the Ukraine; then the Huns when they appeared; then the Vandals in Gaul and Spain. Apparently these amicable warriors had the knack of befriending strangers, unusual in the ancient world; where in many languages the word for “stranger” and “enemy” are one and the same! In Armorica, the Alani and the émigré Britons eventually became one people, the Medieval Bretons; and there is no record of discord between them.

Considering the events to come, in which Ambrosius’ men were to play the key part; and the critical role cavalry were to play (in my opinion) in British warfare from this point forward, it does not seem a stretch to suggest that Ambrosius used his exile in Armorica to recruit from these excellent horsemen.

We don’t know if there was a battle between the returned Ambrosius and the elderly Vortigern. Perhaps the Battle of Wallop occurred now, in the late 450s, and not earlier against his father; and that this was the final reckoning. Or, as seems just as likely, Vortigern, a beaten man beset by failure, simply retreated to his own ancestral homeland, in Wales.

By 460 (if not sooner), Ambrosius was the power in Britain; and Vortigern an exile, dying in Wales soon after. Nennius claims Vortigern was burned alive by "heavenly fire" in the fortress of Craig Gwrtheyrn ("Vortigern's Rock") in north Wales. This may hint at the true story: Accidental or deliberate fire was a real risk in halls made of timber and roofed in thatch. (One tradition has Ambrosius pursuing and killing the deposed ruler in his Welsh fortress. This, however, seems unlikely in the face of Ambrosius subsequent good relations with the old ruler’s family, the rulers of Powys.)

Of Vortigern's young wife Rowena, “the Saxon women”, daughter of Hengist: Nennius' narrative has her die in the same fire that consumed Vortigern and his family. Alternatively, she may have returned to her father and people, in Kent.

Gildas describes Ambrosius as a mild man, a modest man, a Christian man. It was perhaps this trait that allowed him to make peace with the old man he deposed, and to make alliances with his family. Certainly, with the German menace growing in the east, the Britons needed a strong leader to unite, not divide them.

Ambrosius proved to be just such a man.

It is likely Ambrosius took some time consolidating power in Britain. Considering his reputation, it is unlikely he did so in the heavy-handed fashion employed by Vortigern a generation earlier. Instead, he would have revived and reorganized the decaying Roman civil administration, fallen into disrepair during the latter years of Vortigern’s despotism. Elected Magistrates once again administered the towns (civitates), and power was again shifted back to the Council of Britain. Through consensus and persuasion Ambrosius gained the goodwill and cooperation of the confederation of Celtic tribal leaders and Romano-British officials that comprised the leadership of Britain.

Ambrosius was the war leader, however. Through contributions from the tribes and towns, he likely maintained a force of garrisons and a standing body of troops available to respond to crises. This force would have been supported by the levy of the annona militaris, a tax on the local towns and churches of grain and beverage to maintain the Army. The organizational model he likely attempted to reintroduce was that of the late Roman office of the Comes Britanniae ("Count of Britain").

We do not know his actual title, but Count of Britain was the title used by the Roman officer who once commanded the mobile field army charged with defending Britain. Considering his epitaph as the “Last of the Romans”, the modest Ambrosius would have felt most comfortable using this title. However, two generations of Britons had grown up since the Romans had departed; and the current generation had come of age during the 25 years of Vortigern’s reign. They were used to being ruled by one who bore the title of “High King” (which the name “Vortigern” may in fact mean). Had he consented to adopt this most un-Roman of formal titles, however uncomfortably, he would not have revived the hated title of “Vortigern”. So what kingly title would he have adopted?

Perhaps the answer can be found in the sources.


In or about 460, soon after Ambrosius had replaced Vortigern as de-facto ruler of Britain, a Roman official in Gaul, Count Sidonius Apollinaris (later bishop and Catholic Saint), sent a letter to the ruler of the Britons. He addressed the letter to “Riothamus”.

Riothamus will appear again later in the narrative, and has an important role to play. He is a well documented if somewhat mysterious historical character. Most agree that his name is, like “Vortigern”, a title; a Latinization of a Brythonic name meaning “supreme king” or “highest king”: In essence, another title for “High King”.

Could this have been the title Ambrosius used in place of “Vortigern”?

Geoffrey Ashe, , the renowned King Arthur scholar, has identified Riothamus as the true source of the King Arthur legend. He is partially correct.

As will be seen below, elements of Riothamus’ life may well have been the basis for a portion of the Arthur legend. More will be discussed about this later.

But it is impossible that Riothamus can be “Arthur”. Or at least not the only or even chief source of the Arthur legend. Why? Because we know that in/about 460, the date of Sidonius’ letter, Ambrosius Aurelianus was leading the Britons. Unless we are willing to accept that Ambrosius was himself the “real” King Arthur (and I am not).

Ambrosius (and Riothamus) are on the scene too early to be Arthur; 40 years before the average dating by scholars of Arthur’s greatest victory, the defeat of the Saxons at Mount Badon. Arthur cannot be Riothamus; and Riothamus must be Ambrosius (and not Arthur); or some otherwise unknown ruler of Brittany.

Sidonius’ letter to Riothamus asks the “High King’s” help in a routine, administrative matter concerning escaped Roman slaves from Gaul being given refuge in Armorica/Brittany. Some scholars have suggested that Riothamus is the ruler of the Bretons, the British émigré colonists living in Armorica. But this nascent colony was too new and unsettled as of yet to be ruled independent of Britain; and too small to have a “High King”, a title given to one who is “first among equals”, paramount king in a land with many kings, such as Ireland or Celtic Britain.

In the late 5th century, the Britons of Armorica still looked across the channel for their identity, and it was there that their allegiance was given. Sidonius’ letter was sent to the acknowledged ruler of all Roman-Briton’s, Ambrosius Aurelianus; “Riothamus” of Britain.


Even as Aella was christening the South Saxon Kingdom in a Eucharist of slaughter, a child was growing to manhood who would be Briton’s long sought-after savior, and the Saxon’s deadliest foe!

1. Castelden, Rodney, King Arthur: The Truth Behind the Legend, P.82 ; Routledge, 2000

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