That is actually a possibility I've thought of in a previous TL of mine (https://www.alternatehistory.com/forum/threads/dolensi-dolensi-dolensi-dreary-plain.282043/) over a Briton victory at Déols in 469 AD.
If the idea is to have Déols a Briton victory, the primary POD I think as of now involves making Gaul more divided it was IOTL between the 470's and the 520's.
The POD is the Alan kingdom of Orléans surviving Attila's invasion to side with Britons at Déols later.
I should tell the context:
In 455, Avitus, an aristocrat of Auvergne is set on the Imperial throne by Visigoths. In 457, he is overthrown and replaced by Majorian who dispatches Aegidius to Gaul with the mission of restoring Roman authority. He reconquers Lyon and placates the Burgundians before intervening in Frankish affairs because of some troubles and impose Childeric, making a powerdul ally. Meanwhile, Majorian submits the Visigoths and restore Septimania to Roman control.
When Majorian gets assassinated by Ricimer, Aegidius refuse to aknowledge the usurper; with his army, he is de facto the ruler of northern Gaul. Ricimer sends against him the Visigoths (who got Septimania once again after Majorian's death), but they are hugely defeated before Orléans in 463, ending their first attempt to extend into northern Gaul. However, Aegidius dies the year after, either murdered or succumbing to some plague. He leaves an infant son behind, Syagrius, under the care of Count Paul (one of Aegidius' lieutnants).
In 467, Eastern Roman Empire forced on Ricimer the appointment of Anthemius as Western Emperor. After a big failure against Vandals in 468, Anthemius steps in to save the last piece of Gaul still loyal to Rome from the Visigoths: Auvergne. With the Visigoth army of Euric marching on Bourges, the province's capital, Anthemius sets up a coalition against them, made of Saxons, Alans and Britons under the command of Ambrosius Aurelianus, Riothamus or great king of Brittania.
Euric's army is intercepted at Déols. Maybe due to either the support of Orléans' Alans or the support of Eadwacer's Loire Saxons (possible differences from OTL we may don't know of), the battle turns against Visigoths and Euric gets killed.
The strategic consequences are pretty important.
First, Aurelianus returns to Britannia, and rules longer. His succession is more secure, the expansion of Saxons, Jutes and Frisians gets delayed; an instance of this is Aelle of Sussex and his fellow Saxons settling south of the Channel instead, in lower Normandy where there is less opposition.
Second, the Visigoths gets embroiled in a civil war. Euric's infant son, Alaric, gets murdered by one of his uncles (that's not unprecedented I think), uncles who fight. This gives the occasion to Suevi in the Iberic Peninsula to get their revenge on the Visigoths after the defeat and execution 13 years before. At this time, the Suevi seem to be experiencing a resurgence, united under the lead of a King Remismund who did capture Lisbon by treachery this very year (OTL). Remismund disappears from history record after 469 but looks as a guy who could want taking advantage of that civil war to return the Suevi to dominant position in the peninsula.
Meanwhile, an army led by Anthemiolus, Anthemius' son, advances into Septimania and takes Narbonne, restoring Roman control over the region and the land link to Roman provinces in Iberia (the conquest of Tarraconensis by Visigoths is mentioned by the Chronica Gallica only in 473); IOTL, this army was routed by Visigoths and Anthemiolus was killed.
Unfortunately for Anthemiolus and his father, both get killed in 472 by Ricimer.
These events modify the background that led IOTL to the deposition of Romulus Augustus. Finding a way to make the fall of Italy happening in about the same way caused me a writer's block, but I've seen much changed the structure of the TL. The original idea was that Romulus Augustus took refuge in Gaul like Nepos did in Dalmatia, leaving Odoacer in control of Italy. I may still abide by this story, but that doesn't mater as much as it did before.
Then, the political landscape of Gaul in late 470's:
> The area of the Seine and Somme rivers are controlled by Syagrius and Count Paul (as long he lives). For the time being, they are allied to the Franks of Childeric. Of note, the Syagrii are originally a family from Lyon. Trier, on the Moselle heights, is a sailient between Alamans and the Franks, ruled by a Count Arbogast, more or less independent from Soissons.
> Armorica is divided between various Briton chieftains, some of which pledge allegiance to the Riothamus. To their east are Alans and Saxons.
Eadwacer and his Saxons dominate the lower Loire valley, from Nantes to Angers, extractring tribute from cities, but their reach don't go far from the river, excepted in Poitou where they have made some gains at the expanse of Visigoths.
Aelle and his Saxons dominate what is today lower Normandy.
Between them, from the limits of Armorica to the plains of the Beauce, Alans dominate since Aetius settled them here decades ago. One of their main places is Orléans, which is more or less under influence of Soissons, but which has retaken much of its autonomy since Aegidius' death by declaring nominal allegiance to Anthemius and participating to the battle of Déols.
> The Visigoths were settled in Aquitania since the 410's and their Iberian holdings had been a recent result of their intervention against expanding Suevi. Now they lost these lands back to the Suevi, they are confined to Aquitania, but remain a power to count on.
> Auvergne is dominated by the Avitii, a family of prominent aristocrats which produced an Emperor. The bishop of Clermont, Sidonius Appolinaris, a prominent scholar, is tied to this family through marriage ties (his wife was a daughter of Emperor Avitus). Since the death of Avitus, they have remained loyal to what remained of the Western Empire, more by necessity than by genuine loyalism. After the fall of Italy, it has become the core of what remains of the Western Empire, along Septimania and Tarraconensis (which may soon fall to the Suevi ambition though). Since he has taken refuge here, Romulus Augustus has been married to a daughter of Sidonius.
> Burgundians rule over the Rhone valley, and have likely taken Provence to get a spot on the Mediterranean sea. For the time being, they leave Auvergne aside, being busy between their own royal family feuds, Alamans in the north and whoever rules Italy (Odoacer or even Goths if they did invade sooner).
Through the game of alliances, this situation remains more or less the same through years.
In the 480's, Frankish king Clovis, son and successor of Childeric, has turned on Soissons as per OTL but it less lucky here. Syagrius, now in full command (Count Paul is gone), has enlisted the Saxon of Aelle to bolster his ranks, but the decisive factor of Clovis' defeat is the betrayal of Chararic (IOTL, his troops remained out of the fray, waiting to choose the victor's side). Then, family feuds and internal wars, not counting Alaman attacks, prevent Franks from turning again on Soisson before a long time.
As for the Suevi, they may conquer parts of the Ebro valley, but Auvergne could still call on Visigoths and Vandals to check the Suevi.
I've not yet thought of the events between the 480's and the 520's. Still, the perspective of Gallo-roman states surviving into 6th century had interesting consequences when it comes to the days of the Justinian reconquista.
If the idea is to have Déols a Briton victory, the primary POD I think as of now involves making Gaul more divided it was IOTL between the 470's and the 520's.
The POD is the Alan kingdom of Orléans surviving Attila's invasion to side with Britons at Déols later.
I should tell the context:
In 455, Avitus, an aristocrat of Auvergne is set on the Imperial throne by Visigoths. In 457, he is overthrown and replaced by Majorian who dispatches Aegidius to Gaul with the mission of restoring Roman authority. He reconquers Lyon and placates the Burgundians before intervening in Frankish affairs because of some troubles and impose Childeric, making a powerdul ally. Meanwhile, Majorian submits the Visigoths and restore Septimania to Roman control.
When Majorian gets assassinated by Ricimer, Aegidius refuse to aknowledge the usurper; with his army, he is de facto the ruler of northern Gaul. Ricimer sends against him the Visigoths (who got Septimania once again after Majorian's death), but they are hugely defeated before Orléans in 463, ending their first attempt to extend into northern Gaul. However, Aegidius dies the year after, either murdered or succumbing to some plague. He leaves an infant son behind, Syagrius, under the care of Count Paul (one of Aegidius' lieutnants).
In 467, Eastern Roman Empire forced on Ricimer the appointment of Anthemius as Western Emperor. After a big failure against Vandals in 468, Anthemius steps in to save the last piece of Gaul still loyal to Rome from the Visigoths: Auvergne. With the Visigoth army of Euric marching on Bourges, the province's capital, Anthemius sets up a coalition against them, made of Saxons, Alans and Britons under the command of Ambrosius Aurelianus, Riothamus or great king of Brittania.
Euric's army is intercepted at Déols. Maybe due to either the support of Orléans' Alans or the support of Eadwacer's Loire Saxons (possible differences from OTL we may don't know of), the battle turns against Visigoths and Euric gets killed.
The strategic consequences are pretty important.
First, Aurelianus returns to Britannia, and rules longer. His succession is more secure, the expansion of Saxons, Jutes and Frisians gets delayed; an instance of this is Aelle of Sussex and his fellow Saxons settling south of the Channel instead, in lower Normandy where there is less opposition.
Second, the Visigoths gets embroiled in a civil war. Euric's infant son, Alaric, gets murdered by one of his uncles (that's not unprecedented I think), uncles who fight. This gives the occasion to Suevi in the Iberic Peninsula to get their revenge on the Visigoths after the defeat and execution 13 years before. At this time, the Suevi seem to be experiencing a resurgence, united under the lead of a King Remismund who did capture Lisbon by treachery this very year (OTL). Remismund disappears from history record after 469 but looks as a guy who could want taking advantage of that civil war to return the Suevi to dominant position in the peninsula.
Meanwhile, an army led by Anthemiolus, Anthemius' son, advances into Septimania and takes Narbonne, restoring Roman control over the region and the land link to Roman provinces in Iberia (the conquest of Tarraconensis by Visigoths is mentioned by the Chronica Gallica only in 473); IOTL, this army was routed by Visigoths and Anthemiolus was killed.
Unfortunately for Anthemiolus and his father, both get killed in 472 by Ricimer.
These events modify the background that led IOTL to the deposition of Romulus Augustus. Finding a way to make the fall of Italy happening in about the same way caused me a writer's block, but I've seen much changed the structure of the TL. The original idea was that Romulus Augustus took refuge in Gaul like Nepos did in Dalmatia, leaving Odoacer in control of Italy. I may still abide by this story, but that doesn't mater as much as it did before.
Then, the political landscape of Gaul in late 470's:
> The area of the Seine and Somme rivers are controlled by Syagrius and Count Paul (as long he lives). For the time being, they are allied to the Franks of Childeric. Of note, the Syagrii are originally a family from Lyon. Trier, on the Moselle heights, is a sailient between Alamans and the Franks, ruled by a Count Arbogast, more or less independent from Soissons.
> Armorica is divided between various Briton chieftains, some of which pledge allegiance to the Riothamus. To their east are Alans and Saxons.
Eadwacer and his Saxons dominate the lower Loire valley, from Nantes to Angers, extractring tribute from cities, but their reach don't go far from the river, excepted in Poitou where they have made some gains at the expanse of Visigoths.
Aelle and his Saxons dominate what is today lower Normandy.
Between them, from the limits of Armorica to the plains of the Beauce, Alans dominate since Aetius settled them here decades ago. One of their main places is Orléans, which is more or less under influence of Soissons, but which has retaken much of its autonomy since Aegidius' death by declaring nominal allegiance to Anthemius and participating to the battle of Déols.
> The Visigoths were settled in Aquitania since the 410's and their Iberian holdings had been a recent result of their intervention against expanding Suevi. Now they lost these lands back to the Suevi, they are confined to Aquitania, but remain a power to count on.
> Auvergne is dominated by the Avitii, a family of prominent aristocrats which produced an Emperor. The bishop of Clermont, Sidonius Appolinaris, a prominent scholar, is tied to this family through marriage ties (his wife was a daughter of Emperor Avitus). Since the death of Avitus, they have remained loyal to what remained of the Western Empire, more by necessity than by genuine loyalism. After the fall of Italy, it has become the core of what remains of the Western Empire, along Septimania and Tarraconensis (which may soon fall to the Suevi ambition though). Since he has taken refuge here, Romulus Augustus has been married to a daughter of Sidonius.
> Burgundians rule over the Rhone valley, and have likely taken Provence to get a spot on the Mediterranean sea. For the time being, they leave Auvergne aside, being busy between their own royal family feuds, Alamans in the north and whoever rules Italy (Odoacer or even Goths if they did invade sooner).
Through the game of alliances, this situation remains more or less the same through years.
In the 480's, Frankish king Clovis, son and successor of Childeric, has turned on Soissons as per OTL but it less lucky here. Syagrius, now in full command (Count Paul is gone), has enlisted the Saxon of Aelle to bolster his ranks, but the decisive factor of Clovis' defeat is the betrayal of Chararic (IOTL, his troops remained out of the fray, waiting to choose the victor's side). Then, family feuds and internal wars, not counting Alaman attacks, prevent Franks from turning again on Soisson before a long time.
As for the Suevi, they may conquer parts of the Ebro valley, but Auvergne could still call on Visigoths and Vandals to check the Suevi.
I've not yet thought of the events between the 480's and the 520's. Still, the perspective of Gallo-roman states surviving into 6th century had interesting consequences when it comes to the days of the Justinian reconquista.