Everything which happened over the next thirty years was not a series of invasions but a civil war to decide who controlled which part of the empire and, most importantly, who gained the largest proportion of tax. Like many civil wars it turned brother against brother and sons against fathers.
There was an uneasy alliance between Riothemus, Sygerius, Burgundy, the Franks and Rome itself, all nominally working according to the wishes of the then Emperor Anthemius, who was, until he was appointed as the Western emperor a member of the Byzantine court. The Western Empire was still functioning albeit in a modified way. Every menber of the alliance saw themselves as the ultimate victor and therefore the overall co-ordination which in the recent past had been provided by Flavius Aetius, was now missing. Nevertheless Riothemus was not supported by the others during his battles with the Visigoths.
In 468 Ambrosius the uneasy alliance broke and inter-factional fighting commenced. Ambrosius fought against both Saxons and Franks before once again withdrawing to britain
In 470 with the emporer Anthemius in place, Ambrosius/ Riothemus was in Gaul again. the cooperation with the Visigoths had come to an end and the Visigoths were pushing north again making a specific aim of destroying celtic culture They had surrounded Auvern and it is possible that Riothemus aim was to link the territories controlled by Sygerius with Auvern and then with auvern secured to push the Visigoths back to their original land grant south of the Garronne river. It is however also possible that the conflict was initiated by the Visigoths in support of Caswallan.
Riothamus won a battle at Bourges but then suffered suffered a disastrous defeat at Deols. He then sought refuge in Burgundy. Why would Riothamus have taken action independent of Sygerius? It must be suspected that Riothemus was independant of Syagerus or perhaps in competition. He must have weakened the Visigothic position because shortly afterwards a joint attack by Sygerius and the franks under Childeric drove them below the Garronne.
We know about this snippet of history because in 472 Avaranus, the pretorian Prefect for Gaul betrayed Riothemus‘ movements to the Visigoths. Arvandus was subsequently charged with treason against the Emperor Anthemius. The charges are recorded and he was condemned to death but Richimer deposed Anthemius and commuted the death sentence. The new emperor was Olybrius.
Firstly in 472 Richimer died of natural causes. Olybrius died of natural cases immediately afterwards.
The Visigoths followed the lead of the Vandals in declaring their independance from Rome. They ceased to be Foederatii and declared themslves inheritors of the South Western part of the Western empire. They agreed to pay taxes to Rome based on the last census and agreed to give up the eastern part of Septimania in return for the Auvergne.
Britons in Gaul
The British Army declared Ambrosius Emperor ( of the gallic empire) and he defeated Armies sent against him by the Emperor of the East, Leo I.
Ambrosius took control of all of northern gaul and advanced to the Italian border.
There was then yet another rebellion in Britain this time by Ambrosius’ brother Eutherius. The rebellion was defeated but abrosius died shortly afterwards.
After continuing internal strife Eutherius (Euther, Uther Pendragon) defeated his opposition but made no clains as emperor of the gauls.
in 473 Gundobad of Gurgundy, nephew of Ricimar but an ally of Ambrosius declared Ambrosius’ brother in law Glycerous as Emperor of the West
Leo I rejected the appointment and sent Julius Nepos his own nephew as emperor. Orestes, appointed Magister Militum by Julius, was sent to supervise an orderly transition for the administration of Auverne to the Visigoths and he became aware of the magnitude of the transaction, determining that he should be a part of it. He gathered together a group of the smaller nations acting as Feoederatii; Heruli, Scirian and Torcilingi. He marched on Italy and sent Julius Nepos into Exile. There were three emperors of the west Julius Nepos in Norica and Pannonia. Riothemus in northern Gaul and Orestes in Italy
Unfortunately these Foederati employed by Orestes also knew the terms which had been given to both Visigoths and Franks, namely one-third of all land in the territory they occupied. They demanded the same in Italy but Orestes refused. He appointed his son Romulus Augustus as emperor.
Only a year later the foederatii in Italy swiched their allegiance to Odoacer, a junior member of the Visigothic/ Sueve royal family, who defeated Orestes. Odacer deposed Romulus. Odoacer did give the Foederatii what they wanted.
The Senate of Rome told the Eastern Emporer that they no longer wanted a separate Emperor in the West, that they would prefer to be ruled directly from the East. Thus the senate itself had publicly announced the end of the Western Empire.
In 486 Clovis of the franks, son of Clodius, still in his teens, consolidated his possession as High King of the Franks and set about eliminating all his rivals.
Eutherius ignored all this and concentrated on consolidating his hold on Britain.
His period of rule was one of continual conflict but in gerneral was successful. He is best remembered for his seduction (or rape) of Igraine. Eutherius was killed for the rape but Igraine gave birth to an illigitimate son who became known as Arthur.
There have always been overtones of the fact that King Arthur was a “roman” fighting against saxon barbarians. The romano-british fought well in the british isles themselves. the saxons never managed to get a foothold in Wales and it was AD 800 before they conquered Cornwall.
The internal wars and wars against the anglo-saxon invaders continued in britain until 507 when Arthur was recognised as King. In this same year Clovis defeated the visigoths and shortly afterwards drove them beyond the pyrenees apart from a narrow band along the mediterranian coast.
Arthur’s territory included Brittany so he could not ignore events on the continent.
In 488 Theodoric, the Ostrogoth, at the request of the Emperor of the east Zeno, deposed Odoacer and ruled Italy nominally as a viceroy of the Eastern Empire.
He preserved peace with Clovis but on Clovis death in 513 his sons entered into a civil war. Arthur took part in an invasion of Gaul as an ally of Theodoric and managed to not only subdue the fighting but claim northern gaul as part of his own kingdom.
He remained in Gaul for over three years and established his capital at Paris but despite his excellent pedigree never claimed to be Emperor. Perhaps this was the point at which the Western Empire finally ceased to exist. When claiming to be Emperor ceased to have any relevance.
The British Saga
Whilst he was away his half sister Morgan le Fay and Athur’s son by her Mordred, rebelled against him and the advance of the Anglo Saxons gathered pace.
Arthur initially tried to deal with the rebellion as an Emporer would by sending comes to Britain to deal with the rebellion. The rebels knew that the comes did not have the invincible power of Rome behind them , they were just another faction in the struggle for power. In the end Arthur returned to England in 517, never to return to his possessions in Gaul which reverted to the Franks. Not only the Gallic empire but all dreams of a Gallic empire were finally extinguished.
From 527 onwards now confident that the celtic culture had been destroyed Justinian the eastern emporer and his famous General Belisarius, set about reclaiming their empire.
He reclaimed Africa from the vandals, southern Hispania from the visigoths, Italy and Illyrica from the ostrogoths but it proved to be Ephemeral. Gaul remained beyond his reach and now transformed as an independant kindom of Frankia, by no means a celtic state.