Although the term Vortigern is considered as an epithet by most scholars, no one to date has linked this epithet to the proper name Æternus, who is recorded in Welsh genealogies as son of Paternus of the Red Robes, father of Cunedda, and grandfather of Cerdic. He is likewise considered by some that he is the superbus tryrannus referred to
by Gildas Badonicus in the De Excidio. 

ÆTERNUS>VORTIGERN

SUPERBUS TYRANNUS

Briton figures of the fifth century are some of the most intriguing and elusive individuals to identify, and Vortigern is no exception.  A majority–but not unanimous–number of scholars and researchers agree that the term Vortigern is an epithet, meaning “Over Lord” or something synonymous.  Gildas Badonicus wrote of the superbus tyrannus, which in itself is obviously another epithet, but he does not identify by name who this superbus tyrannus is; it is Bede of a later century who names Vortigern as the superbus tyrannus, and a great number of later antiquarians and modern historians jumped on the bandwagon regarding Bede’s switch to be an irrefutable fact.  All that does, however is substitute one epithet with another.

Leslie Alcock attacks the question with an initial reminder that

We have still to explain the emergence of the superbus tyrannus of Gildas out of the framework of Roman civil administration.  Our only clue to the constitutional processes involved is the word (superbus) tyrannus itself.

A quick survey shows that superbus tyrannus has variously been defined as high king, supreme ruler, great king, over-lord, haughty tyrant, and most commonly, proud tyrant.  As a parallel, the epithet “Vortigern” is most commonly defined, as suggested above, as over-king or over-chief.  Additionally, both Alcock and Ashe refer to Vortigern as a usurper.  As an interesting parallel, Ashe writes of Vortigern as having “power without legitimacy,” which he echoes in his article for The Arthurian Encyclopedia, claiming Gildas’s superbus tyrannus implies “not so much tyranny as doubtful legitimacy.” After a great deal of deliberation and close scrutiny of Briton history, The Historic King Arthur deviated from Bede’s proclamation and reached a different conclusion:  the superbus tyrannus mentioned by Gildas Badonicus in the De Excidio is a reference to Valentinian III, and by extension, Vortigern is a different epithet for a chieftain appointed as an “over-king” of the mercenary tribes on the island, who would have accepted the edict of someone much more powerful, following what was typical Roman policy.  The word tyrannus means “an absolute ruler,” although sometimes it was used by Ovid and Cicero to mean someone who overthrows the constitution of his state.  The adjective superbus means “exalted” which has a range of interpretations from “arrogant” or “overbearing” to “magnificent” or “splendid.”  None of those terms would refer to Vortigern, who earned the hatred of all the succeeding Britanni generations.  Had Gildas Badonicus meant to label the superbus tyrannus as a usurper, he would have used a much more explicit expression such as regnum occupare, “to seize the throne,” or “to seize authority,” rather than using the obscure connotation “usurper” attached to the word tyrannus.  If the name Valentinian is substituted for Vortigern, the passage clearly makes more sense; Valentinian as Emperor of the Western Empire, would be following age-old policy of using foederati to fight against the enemy.  Co-Emperor Constantius III died in 420; Emperor Flavius Honorius died in 423; Valentinian III succeeded to the throne, but because he was very young, his mother Galla Placidia was appointed as his Regent.  All of these changes occurred about a decade after the withdrawal of Roman troops from the island.  Vortigern appears on the historic scene around the year 425, and since no Roman troops could be sent to the province, Galla Placidia, acting as Regent in behalf of Valentinian, followed typical Roman protocol and assigned Æternus (i.e. Vortigern) as Overlord of Britannia Prima, who in turn recruited Anglians as foederati.

Section 31 of the Historia Brittonum introduces Vortigern: 

Vortigern ruled in Britain, and during his rule in Britain he was under pressure, from fear of the Picts and Irish, and of a Roman invasions, and, not least, from dread of Ambrosius. Then came three keels, driven into exile from Germany.  In them were the brothers Hengest and Horsa. . . Vortigern welcomed them, and handed over to them the island that in their language is called Thanet and in British Ruoihm.

Piecing together information from other sources, Vortigern is Welsh, and his homeland can be placed with assurance in southwestern Wales.  A different section of the Historia Brittonum (Section 14) relates that Cunedda expelled the Liathan clan from Gower and Kidwelly, now a part of Carmarthenshire.  A second of Vortigern’s fears was that the Romans would return and punish or kill him if he was not a successful Overlord.  His primary fear, however was that Ambrosius Aurelianus, a Roman whose father was a consulibus, would claim his rightful position as Overlord.  What probably caused the so-called exile of “Germans” was that the West was attempting to ease the pressures and incursions of the barbarians in Gaul, and one way to do that was forcible migration.  That Vortigern welcomed them to the island suggests Hengist and his tribe were bribed by the West to become foederati.

The jarring perplexity of that segment is the last sentence, Vortigern giving them territory in Thanet, which future generations have blandly accepted as the Isle of Thanet in Kent.  Vortigern’s kingdom was part of Roman Britannia Prima, but the kingdom he gives away is part of Roman Britannia Secunda.  Vortigern’s kingdom was named Dyfed, and the distance to the Isle of Thanet would be around three hundred miles away, a highly unlikely distance for Hengist to commute if he were in league with Vortigern to fend off the Picts and the Irish.

The real key to determine where Hengist’s kingdom might have been located according to the information recorded in the Historia Brittonum are the locales Tanet and Ruoihm.  Eilert Ekwall’s etymology for Tanat (note the difference in spelling) is as follows:

A Brit river-name identical with Old Welsh tanet in personal nouns and meaning ‘brilliant river.’  Old Welsh tanet is derived from tan ‘fire’.

Thanet, then, is probably not a cognate of Tanet, but even if it is, the Isle of Thanet is not feasible as Hengist’s new kingdom.  The word is Old Welsh, suggestive of a Welsh location.

A philological check for the other name given–Ruoihm– is even more revealing.  Of the seventeen or so variant manuscripts of the Historia Brittonum, Josephus Stevenson lists nine different spellings:  Ruoihin, Ruichun, Ruoichim, Ruoichin, Ruithina, Rudithin, Ruithon, Ruoithin and Roihin.  A scrutiny around the area of the River Tanet does not contain such a name, but Ruoithin is a cognate of Ruthin, approximately twenty miles due north of the River Tanet.  A historical check shows that Ruithin was one in a string of hillforts extending from Moel Hiraddug on the coast, to Pen y cloddiau and then from Moel y Gaer and Foel Fenlli to Ruthin.  The chain parallels not only the Clwydian Range, a demarcation and protective shield between Wales and the barbaric northern interior of the island.  This in itself makes more sense; Hengist is indeed in a position at this location to protect Wales from  a northern attack.  Offa’s Dyke, too might have functioned as a barrier.  (See Walls of Britain.)

Vortigern’s second appearance is a lengthy segment covering Sections 36 to 49, which stresses the importance of Vortigern’s role in Welsh history.  Skimming through Sections 36 through 38, Hengist multiplies his numbers, and realizing Vortigern’s ineptitude and military weakness, more envoys came across the sea, and in one of the keels was Hengist’s unnamed daughter.  Satan enters Vortigern’s heart, and in a trade Vortigern bartered extensive lands for Hengist’s daughter.  Once again the land is erroneously situated in Kent, “although Gwyrangon was ruling in Kent.  The name of that Kentish king is perplexingly Welsh, but Stevenson unknowingly supplies an explanation circumventing Kent as the location.  In a footnote, he writes that the name Gwyrangon– which has eight variants–is not actually a proper name, but an epithet which means a governor or sub-king.  Section 38, too, disclaims Kentish territories, for Octha and Ebissa go to the far, far north as far as the borders of the Picts, which would cover more than two-thirds of the entire island.

Sections 40 through 42 are crucial, particularly because Ambrosius Aurelianus enters the scene.  “The Tale of Emrys” shifts
to the northern Welsh peninsula of LLeyn, at Dinas Emrys, the fortress of Emrys, one of Ambrosius Aurelianus’s epithets.  When Ambrosius confronts Vortigern and his magi, they flee further to the north in Gwynedd where Vortigern builds a fortress named after him, Gwytherin.

In Sections 45 and 46 Vortigern is reinstated as king after Vortimer is poisoned.  Hengist and his host return, and Hengist treacherously slaughters the Council of the Provinces, all except Vortigern.  To save his life, Vortigern ceded several districts, including Essex and Sussex, plus Middlesex and other sites that the Anglians chose.  Sections 47 describes his rejection and exile.  Saint Germanus attempts to force him to change his ways, but Vortigern withdraws in disgrace, escaping to his fortress in Dementia.  His fortress is  destroyed by fire from heaven, and all who were with him were consumed.  Section 48, however, offers different circumstances of his death.  One is that he wandered from place to place until at last his heart broke and he died without honor.  Another relates that “the earth opened up and swallowed him on the night when his fortress was burning around him, for no trace was ever found of those who burned  with him in the fortress.”

Like The Historia Brittonum, Geoffrey of Monmouth portrays Vortigern as a villain, but in a more graphically detailed narrative.  After the death of Constantine, there was bickering as to which of the three sons should become the next king when Vortigern appears on the scene.  Because Aurelius Ambrosius and Utherpendragon are too young to inherit the throne, Vortigern sets up Constans as the puppet king and plots to seize the throne of Britain.  Once in power, he deceitfully structures a story that the Picts are threatening to attack Britain, but instead he befriends the Picts and convinces them to kill Constans.  Once that is done, he has the Picts killed and he crowns himself as king.  Aurelius and Utherpendragon are spirited away to Brittany for fear that they would be assassinated.

Hengist and Horsa arrive in Britain, and Vortigern accepts them as allies.  More Saxons are invited over, and among them is Renwein, Hengist’s unnamed daughter in the Historia Brittonum.  Vortigern lusts after her, and she is given to him in exchange for the kingdom of Kent.  Vortigern falls into disfavor with his own people, and is dethroned by Vortimer, his eldest son, who wins four battles against the Saxons.  But Renwein plots the poisoning of Vortimer, and Vortigern once again ascends to the throne, but when he invites the Saxons back, he is terrified by their numbers and tries to resist.

Hengist then plans and carries out the slaughter of the Council of the Provinces.  Everyone is killed, except a hero named Eldol.  Vortigern is held for ransom, and after his release, he flees to Wales where he attempts to build a fortification.  He summons his magicians (where did they come from?) and they tell him that he must find a fatherless lad and kill him to sprinkle his blood in the mortar and on the stones.  Paralleling the tale of Emrys in the Historia, Ambrosius Aurelianus, who was also called Aurelius Ambrosius, the newly anointed king.

Ambrosius is enraged by Vortigern’s multiple transgressions.  He attacks the castle in Kambria where Vortigern had fled for refuge.  Ambrosius and his army

. . . lost no time, but moved into position with their seige-machines and did their utmost to break down the walls.  When everything else had failed, they tried fire; and this, once it took hold went on blazing until it burned up the tower and Vortigern with it.

The account in the Brut Tysilio is much the same as Monmouth’s narrative.  Once Emrys is crowned king, his objectives are to first seek revenge against Vortigern and then against the Saxons.

It was first resolved here to attack the Castle of Goronwy, which is in Erging on the Wye, and whither Vortigern had fled.  Hither Emrys came with a large army, and addressing his troops, told them that in that castle was the man who had been the occasion of the death of his father and his brother, and had brought the treacherous and infidel Saxons into the island.  The army thus addressed assailed the castle with vigour, soon set it on fire, and burned it  and all in it, Vortigern included.

Thus ends the story of Vortigern.