Legend says that Vortigern was an official at the court of the Emperor of Britain, Constantine Waredwr (the Deliverer), in the early 5th century. He climbed his way high up by securing an inspired marriage to Severa, the daughter of the Emperor's predecessor and national hero, Magnus Maximus. Rising to be chief advisor, Vortigern had the Emperor deposed while he was away campaigning on the continent. He then temporarily placed the Emperor's eldest son, Constans on the throne while he brought his Pictish relatives to court to consolidate his position. Vortigern used these Northern henchmen to dispose of the three people standing between him and the British crown. Constans was assassinated, but his young brothers were bundled up and escaped to the court of their cousin, Budic I, in Brittany.
It was during Vortigern's reign that St.Germanus visited Britain, from Auxerre, to stamp out the Palagian heresy that had become so popular. His first journey took him from Caer-Rebuti (Richborough) to Caer-Lundein (London), Caer-Mincip (St.Albans) and up to what is now Cheshire where he led an army against a party of invading Saxon pirates. Germanus was greeted by the High-King himself on his return, some years later. The saint spent a little time at the royal court, probably Caer-Guricon (Wroxeter, Shropshire) where excavation has revealed the residence of a powerful 5th century noble. Here the saint accused Vortigern of fathering a child by his own daughter. Though disgusted by the British High-King, Germanus favoured the man's sons, three of whom he appears to have blessed.
Even with the support of his brothers-in-law, who were now powerful rulers in Wales, Vortigern's grip on the country was still shaky; but when Severa died the situation worsened and he was forced to bring in Saxon and Jutish mercenaries, led by Princes Hengist & Horsa, to stabilize things. The two brothers asked, as a reward for quelling all resistance, for all the land they could cover with a single ox-hide. Vortigern eagerly agreed, but found that Hengist cut the hide into a lengthy thong that was able to encompass the whole city of Caer-Correi (Caistor, Lincs)! The Saxons were as good as their word though, and control of the country soon returned to Vortigern's hands. Later, however, they tricked the High-King again: this time into handing over to them the Sub-Kingdom of Ceint (Kent). Getting drunk at a celebratory feast, the foolish Vortigern fell deeply in love with Hengist's daughter, Rowena. He promised Hengist anything he wanted, if only he could marry her. Ceint was the Saxon's price.
Sickened by the betrayal of his countrymen, Vortigern's eldest son, Vortimer, declared himself a rival British leader, raised an army and, for a short time, managed to stem the Saxon advance. Wounded in battle, however, he was poisoned by his step-mother. From their secure power-base, the Saxons saw their chance and rebelled against Vortigern. They tore through the land, leaving devastation wherever they went. Many were killed during the ensuing battles, amongst them, Horsa & Vortigern's son, Catigern. Hengist eventually called for a peace conference on Salisbury Plain. The British arrived and were promptly cut down where they stood.
Vortigern escaped to set up a stronghold in the west. He chose to build a castle on the southern slopes of Yr Aran, above Beddgelert (Gwynedd). Construction began. However, every morning the previous day's work was found demolished. Vortigern's magicians told him to seek a boy with no father, born of the fairies. He would be able to solve the High-King's problem. Vortigern's men searched far and wide and discovered such a boy at what was soon to become Caer-Myrddin (Carmarthen). His name was Myrddin Emrys, or "Merlin" for short. Merlin revealed that at night the mountain shook so that all buildings collapsed, because beneath it were buried two fighting dragons. One white representing the Saxons and one red representing the British, and the white one was winning! Afraid of such an omen, Vortigern fled.
Disillusioned, the British finally rebelled against their High-King and Constantine's son, Ambrosius Aurelianus (Emrys Wledig), now a burly young man, returned to lead their struggle. Merlin handed over to him the mountain site where Vortigern had failed to build, and it became his fort of Dinas Emrys. Vortigern took refuge in a wooden castle on the refortified hillfort of Caer-Guorthigirn (Little Doward) above Ganarew, but it was miraculously struck by lightning and he burnt to death. He was later buried in a small chapel in Cwm Gwrtheyrn on the Lleyn Peninsula.

Vortigern Vorteneu (W. Gwrtheyrn Gwrtheneu) was the British High-King notorious for allowing the Anglo-Saxons and Jutes to overrun his country, having initially employed them to defend its shores
Vortigern's name has been taken to be a title, Gwrth-teyrn, literally meaning "Most Above Prince": Over-King is the usual interpretation. Though similar names were used for other monarchs and the addition of an epithet to a title seems unlikely, "Over-King" does describe exactly Vortigern's traditional position in British Society. There is further evidence to support the theory. Vertigernus was the title first used by Bede in his "Chronica Majora" (725), though his basic information came from Gildas who used the alternative term of 'Superbo Tyranno' (Supreme Tyrant) in his "De Excidio Britanniæ" (c.545). The term Gwrtheyrn appears to have been extensively used in Wales and spread, via Bede's anglicized Vortigern, throughout both the British and Saxon parts of the Island.
In his "Historia Brittonum" (c.830), Nennius records that "From the reign of Vortigern to the discord between Guitolinus and Ambrosius are twelve years". But should this be interpreted as twelve years from the beginning or the end of Vortigern's reign? A modern reader might instantly take this to mean from the end of the reign. However, it seems that 9th century readers thought differently. It was therefore not until twelve years into Vortigern's reign that Guidolinus and Ambrosius had their falling out. Nennius specifically recorded, and it has generally been accepted since, that Ambrosius was Vortigern's major adversary. It would therefore seem logical to identify Guidolinus (L. Vitalinus) as Vortigern's real name. Moreover, Guitaul (L. Vitalis) and Guitolin (L. Vitalinus) are given in Nennius and the Jesus College MS 203 as the father and grandfather respectively of Vortigern. It has been suggested by John Morris that "Vortigern son of Vitalis son of Vitalinus" may have been a mistranscription of something like "Vortigern that is Vitalinus son of Vitalis".
Vortigern usurped power over the whole of the Island of Britain as High-King, apparently setting up a system of strongholds across the country, stretching, at least, from Caer-Ligualid (Carlisle) to Caer-Baddan (Bath). Though those that remain are all in the west
Vortigern, however, is also specifically recorded, by Nennius, as a ruler of the Regio Guunnessi (Gwent7). This was his original kingdom, probably inherited through his first wife Severa's ancestry, as shown by her mother's supposed descent from the legendary Kings of Siluria. His own family appear to have originated in neighbouring Caer-Gloiu (E. Gloucester).
Nennius mentions only four sons who could have inherited Vortigern's kingdom: Guorthemir (E. Vortimer/W. Gwerthefyr), Categirn (W. Cadeyrn), Pascent (W. Pasgen) and the incestuously begotten Faustus by an unnamed daughter. However, we know from other sources that there were further sons including Brydw and St.Edeyrn of Llanedeyrn, and a possible daughter, Scothnoe.
After Vortigern's dramatic demise at the hands of his old enemy, Ambrosius, it was his son Pasgen who, according to Nennius, was allowed to rule the Powysian sub-Kingdom of Buellt and Gwerthrynion, due to the magnanimous generosity of the new High-King.
So, although Vortigern's reign has been remembered in history and legend as the most disastrous to have ever befallen the British Nation, he did manage to leave a powerful legacy to his sons. He established them so well in the rich kingdoms in the heart of Britain that his family ruled there for the next eight hundred years.