Gaul Rising

This is an alternate timeline in which the Gallic Empire, which in our timeline was a short-lived breakaway state from the Roman Empire, manages to hold on to its independence.

Author's note: I would appreciate any suggestions you have. You can either post suggestions on the article's discussion page or my own talk page. I am also okay with you making minor edits, such as spelling or grammar corrections; but I would prefer that nobody other than me make major additions or revisions. Thank you and enjoy this timeline.

 Pacificus   Viridis 

The Crisis of the Third Century
For much of the Third Century, the Roman Empire was in a constant state of civil war.

It began in 235 AD, when Emperor Alexander Severus was murdered by his own troops, who felt he was not being aggressive enough in dealing with a Germanic invasion of Gaul. Alexander Severus' forces declared Maximinus Thrax the new Emperor. Thrax was not popular in the Roman Senate, so when Gordian, the governor of the province of Africa Proconsularis, rebelled in 238, the Senate proclaimed him and his son Co-Emperors. The rebellion failed, but the Senate appointed another pair of Co-Emperors as Thrax was preparing to march on Rome to punish the Senate. The Senate's choices were unpopular among the masses, so the masses declared Gordian's grandson Emperor. This led to anarchy in the city. Meanwhile, Thrax's invasion of the city failed, so his troops killed him out of dissatisfaction.

The downfall of Alexander Severus, the reign of Maximinus Thrax, and the rebellion of Gordian I and Gordian II were the start of a vicious cycle in which a general or provincial governor would rebel against the current Emperor, possibly gain the acceptance of the Senate, immediately have to deal with an external invasion or rebellion, and in many cases be killed by his own troops, who would then align themselves with a new contender for the throne. Generals turned their attention more toward fighting each other than protecting the Empire's external borders, which led to frequent invasions by barbarian tribes. Another problem that resulted from the constant civil war was severe inflation: each time someone would declare himself Emperor, he would promptly have a large supply of coins with his face on them minted to pay his troops. This state of affairs lasted for decades.

The Rise of Postumus
Marcus Cassianius Latinius Postumus was appointed governor of the Roman border province of Germany Inferior by Emperor Valerian during the 250s. Valerian ruled from 253 to 260 alongside his son, Gallienus. After Valerian died, Gallienus reigned alone. In 258, Gallienus appointed his son, Salonius, a subordinate emperor.

In 260, Valerian was waging a campaign against Persia (which resulted in his capture and execution by the Persians) and Gallienus and his forces went to Pannonia to deal with a rebellious general. Postumus, Salonius, and Salonius' mentor, Silvanus, were tasked with defending the Rhine frontier. They were stationed at Colonia Agrippina (Cologne).

Now on October 25, 260, Postumus and his forces intercepted an army of Juthungi (a Germanic tribe) that was returning home from a battle at Mediolanum (Milan). The Juthingi had lost the battle but nevertheless managed to carry off captives and other booty. Postumus's army defeated the invaders and then divided their loot among themselves. Salonius, at the recommendation of Silvanus, ordered Postumus to hand over the loot to him. Postumus and his troops refused, and Postumus' troops declared him Emperor on November 2. Postumus and his army then laid seige to Colonia Agrippina. On December 9, Salonius and Silvanus surrendered and allowed Postumus and his forces into the city, and were thereafter executed. Ever since then, December 9, 260 has traditionally been considered the date that Postumus' reign officially began.

Postumus was immediately recognized as Emperor in the Gallic provinces (except for Gallia Narbonensis), Germania Inferior, Germania Superior, and the Alpine province of Raetia. Within a year, the Britannian and Spanish provinces also aligned themselves with Postumus; and Gallia Narbonensis followed a year later. Postumus made Colonia Agrippina the capital of his realm and set up a system of government similar to that of Rome as it was before the death of Alexander Severus. The coins minted under his authority were of an unusually good quality for coins for those days. Rather than seeking control of the rest of the Roman Empire, Postumus focused on defending and bringing stability to the provinces he ruled; and he was indisputably successful at achieving this goal.

Gallienus had to leave Postumus alone for several years, as Germanic tribes were constantly invading the areas still under his control. He challenged Postumus for the first time in 265, sending Aureolus, a general loyal to him, to invade the breakaway provinces. The campaign failed as a result of carelessness on the part of Aureolus. Two years later, Gallienus himself invaded Postumus' realm, but this invasion also failed. Gallienus did manage to retake Raetia in the latter half of 266.

Point of Divergence
The point of divergence between this timeline and ours occurs in 268. Aureolus, who was at that time stationed in Mediolanum (Milan), openly defected to Postumus. Gallienus promptly led an invasion of Mediolanum.

What Happened in OTL
Postumus chose not to come to Aureolus' aid. Gallienus' forces laid seige to Mediolanum. During this time, Gallienus' senior officers murdered him and proclaimed Marcus Aurelius Valerius Claudius (Claudius Gothicus) Emperor. Aureolus surrendered to Claudius II, only to be executed thereafter.

Postumus' decision not to help Aureolus marked the beginning of the end of his rule. His armies became discontented with him, which is evidenced by a sudden decline in the quality of the coins issued under his authority in 268: he had more coins produced in an effort to buy the loyalty of his troops. One of his generals, Laelianus, declared himself Emperor. Laelinus was stationed in Moguntiacum (Mainz), so Postumus led forces that were still loyal to him to invade Moguntiacum. Postumus defeated Laelinus, but then forbade his soldiers to plunder the city. For this, they murdered him and proclaimed Marcus Aurelius Marius the new Emperor.

Thereafter, the territory Postumus had controlled fell into the same state of disorder that the Roman Empire as a whole had fallen into more than thirty years before. Postumus' realm became increasingly weak; and in 274, Roman Emperor Aurelian reconquered what was left of it.

What Happened in This Timeline
Postumus decided to lead a campaign to Mediolanum to help Aureolus out. The combined forces of Postumus and Aureolus managed to repel Gallienus' campaign. Gallienus' senior commanders, who wanted him dead anyway, murdered him and proclaimed Marcus Aurelius Valerius Claudius the new Roman Emperor.

The Remainder of the Reign of Postumus
Postumus' victory at Mediolanum was an important one. The direct result of the victory was that he now had an ally in Aureolus and control of Mediolanum and the surrounding area. Postumus never intended to invade Rome; but he did anticipate that doing so could be necessary as a defensive action, and Mediolanum would be an important point from which to launch such an invasion should he deem it necessary. Also, Postumus would now be able to invade Raetia on two fronts, one being from the west and the other being from the south. The area also served as a buffer between Roman territory and Postumus' core territory.

Claudius II, the new Romen Emperor, had to immediately turn his attention to the Balkans and the Agean Sea, where various Germanic tribes were carrying out a massive naval invasion. Claudius II was able to drive out the invaders after the Battle of Nassius. This was an important victory for the Roman Empire as it neutralized the threat of the Germanic tribes north of the Danube for decades. After the victory, Claudius II took the title "Gothicus".

Shortly thereafter, an army of Alammani and Juthingi invaded Raetia. Armies loyal to Postumus came to the aid of the forces stationed in Raetia before Claudius II could arrive, and the combined forces sucessfully repelled the invasion. The governor of Raetia, in gratitude, aligned himself with Postumus.

Claudius II began planning to invade Postumus' realm, but he was forced to put his plans on hold in order to travel to Pannonia to deal with Vandal raids. Before he could engage the Vandals, however, he died of smallpox in January 270. He was succeeded by his brother, Quintillus, who in turn died and was succeeded by Aurelian by September 270.

Early Administrative and Constitutional Reforms
In 271, Postumus established a clear procedure for imperial succession. This was an important constitutional reform, because one of the original causes of the political instability in the Roman Empire was a lack of such a formally defined procedure, so the establishment of a formal process offered the promise that Postumus’ empire could remain internally stable long after his death. It was also significant because it gave the Senate some say in the process of imperial succession. The guidelines he established were as follows: the Emperor could designate a person to succeed him upon his death or abdication; and if the Emperor were to die or abdicate without a designated heir, the Senate would have the exclusive power to elect a new Emperor. In 274, he also gave the Senate the power to depose the current Emperor, provided that the Senate first come to an agreement upon who the new Emperor should be. The purpose of this second edict was to discourage armed rebellions against unpopular Emperors.

Postumus also began reorganizing the provinces under his rule during this time. At first, the changes he made were rather modest. In 271, he divided the province of Lugdenensis into smaller provinces. Then in 273, he formed two new provinces from parts of Aquitania. More significant reforms, including changes to the actual administrative structure of the provinces, would come later.

Prelude
At the time that Aurelian became Roman Emperor, Postumus was still in a very good position. From his capital in Colonia Agrippina, he ruled over Gaul, Spain, Britannia, Raetia, and the majority of the northwestern Italian region of Transpadana (this was the area that surrounded Mediolanum). He had successfully defended his domain from external invasions. While the main empire was still tormented by civil war and external invasions, Postumus' empire was enjoying a state of stability and prosperity unknown since the death of Alexander Severus. Postumus' popularity had grown, especially after his battle against Gallienus at Mediolanum and the campaign against the Germanic invaders of Raetia that led to Raetia voluntarily rejoining his empire.

Yet Postumus' success was partially the result of mere luck. If Gallienus did not have to spend several years fighting off Germanic invaders, he could have confronted Postumus before Postumus had a chance to consolidate his authority. The invasion led by Aureolus in 265 mainly failed as a result of carelessness on his part. Gallienus had managed to defeat Postumus by retaking Raetia in 266, though Postumus reversed that defeat in 269. Postumus would not be in control of Mediolanum if Aureolus had not defected to him, and maintaining control of Mediolanum would have been more difficult for Postumus if Claudius II had not had to deal with the major Germanic invasion in the east. It was from Aurelian that Postumus would receive his first major challenge.

Aurelian did not take any action against Postumus until 275. For the first couple of years of his reign, he successfully contended with Germanic invaders. Then in late 272 and early 273, he turned his attention to recovering Egypt and the Asian provinces, which had become part of a breakaway empire similar to that of Postumus. Aurelian was able to bring the entire breakaway empire, known as the Palmyrene Empire, back under Roman rule in a matter of months. One action considered a key to his rapid victory over the Palmyrene Empire was that he had refrained from sacking the city of Tyana after taking control of it. As a result of the mercy he showed to Tyana, many other cities in the Palmyrene Empire opted to peacefully surrender. Aurelian conducted several other campaigns after this one, and then prepared to go to war with Postumus.

Aurelian's invasion
Aurelian began his attack in early March 275. Unlike Aureolus and Gallienus, who had only tried to invade by land from the east, Aureolus launched two naval invasions: one, led personally by him, would sail from Corsica to Narbonensis; and the other one, led by a reliable general named Aurelius Marcellinus, would sail from Mauretania Tingitana to Baetica. Aurelian also had another general under his command named Iulius Placidianus lead a land invasion. At first, Aurelian's forces were successful on all three fronts. Half of the units consisted exclusively of cavalry, and were therefore more mobile than traditional units, which consisted of a mix of cavalry and infantry. They took large swathes of land in Gaul and Spain.

By the middle of May, however, progress had begun to stall for Aurelian's forces. The land invasion had proven unsuccessful. Postumus had built up defenses in Raetia and Transpadana to a greater extent than Aurelian's spies has estimated. Placidianus also made the mistake of choosing to bypass the areas where troops loyal to Postumus were most heavily concentrated. His hope was for them to rush through Transpadana and begin seizing territory after reaching the minor Alpine princes. Instead, those units found themselves trapped. Approximately half of the soldiers fighting for Aurelian were killed in a fierce battle. The majority of the survivors chose to go deeper into enemy territory. Meanwhile, Postumus and his generals had had time to organize their forces to counter the attacks in Gaul and Spain. Postumus had been creating cavalry-only units since 272, and he ordered his generals to reorganize some of their units accordingly. These units proved effective at countering Aurelian's units several times during late April. Aurelian had also underestimated the loyalty of the masses to Postumus. Under Postumus, the people had enjoyed fifteen years of uninterrupted stability and prosperity; whereas the rest of the Roman world had continued to suffer chaos for years. The majority of the people believed that they owed Postumus everything and owed Aurelian nothing. Since the invasions began, many fighting-age civilians in Gaul, Spain, and Britannia had enlisted in the army under Postumus' control.

The Invasion of Italy
In late May, Postumus planned an invasion of Italy. One of his generals, Laelianus, was to lead a large naval force from southwestern Gaul to central Italy. Meanwhile, another general, Victorinus, would lead a land campaign south from Mediolanum. The plan was for both groups to converge at Rome and sack it. Also, there was a third army loyal to Postumus that had gradually sneaked into southern Italy, a few men at a time, between 271 and 273. This "sleeper army", commanded by Julius Saturninus, had maintained contact with Postumus' empire, and now Postumus decided it was time for them to act: their mission was to wreak havoc in southern Italy to make it so that Aurelian's forces could not be concentrated in northern and central Italy.

A group of four ships set sail from southwestern Gaul to southern Italy in the middle of June. Their mission was to provide instructions to the sleeper army. A few days later, Laelinus' forces set sail for central Italy. Three days after that, reinforcements summoned by Aurelian arrived in southern Gaul.

The instructions to the sleeper army arrived in early July, and the group was fully assembled within a week. On July 17, they began to attack cities and towns in southern Italy. The march from Mediolanum to Rome began on July 18, and the naval invaders from southwestern Gaul landed on July 22. Laelianus' forces reached Rome by July 24 and began laying a siege to Rome. Victorinus' troops joined them on August 3. The invading forces could not simply enter the city because Aurelian had recently had a wall built around it. The invaders began digging siege tunnels on July 26. Aurelian learned of trouble in Italy by August 4. By August 19, two tunnels had been completed and the invaders poured into Rome.

The invasion of Italy exceeded Postumus' expectations. Postumus correctly anticipated that the invasion would make it necessary for Aurelian to send some of his troops back. He also knew that the sack of Rome would serve as a severe embarassment to Aurelian: the city of Rome had not fallen to invaders since 387 BC. Moreover, by the middle of September, word had reached both Postumus and Aurelian that the Senate had evacuated Rome on August 27. (Forcing the Senate to evacuate Rome was not part of Postumus' plan, but was a goal that the generals leading the invasion had agreed upon several days before the sack began.) The sack of Rome lasted until September 6, after which the forces under Postumus' command left and went on to plunder other cities in central and northern Italy.

After Aurelian learned of the details of the sack of Rome, he sent half of the reinforcements that had come to him in June to Italy to deal with the invaders. He also ordered Aurelius Marcellinus to send half his forces to Italy, even if it meant having to pull out of some areas that he had already secured. In light of the invasion of Italy, Aurelian's strategy was to neutralize the invaders of Italy and at the same time get to Colonia Agrippina as quickly as possible. Then, after doing those two things, he could devote as much manpower, money, time, and resources as he needed to restoring Roman authority over Gaul, Spain, and Britannia. Postumus had expected that Aurelian would try to take Colonia Agrippina as soon as possible, so he had already increased the defenses near the city.

The Germanic Invasion
Back during late April, Postumus had sent envoys to the Alammani, Suevi, Marcomanni, and Quadi. The envoys were instructed to propose an alliance between the tribes and Postumus' empire. The plan was for the tribes to invade Pannonia and Noricum; and in return, Postumus would consent to those tribes permanently controlling the territory of those two provinces, so long as they did not subsequently invade his territory. The leaders of the Suevi declined the offer, but the leaders of the other three tribes accepted, on the condition that Postumus develop and execute a workable plan for his own forces to invade another area under Aurelian's control. In the middle of September, the leaders of the three tribes that had conditionally agreed to the alliance informed Postumus that they would invade Pannonia and Noricum.

The allied tribes began their invasion in late October. Aurelian's empire was caught off-guard, so the participating tribes managed to take a fifth of both Pannonia and Noricum within three weeks. After this, the local Roman generals were able to slow the invaders' progress. News of this did not take long to spread, and the Vandals and the Gepids opted to take advantage of the situation: by late November, they had crossed the Danube and begun to invade the Balkans.

Political Fallout Begins
Prior to his war against Postumus, Aurelian had reconquered the Palmyrene Empire, actively combatted corruption, and improved the coinage; and for this he had steadily gained popularity. The sack of Rome — and the invasion of Italy in general — was a severe blow to his popularity. Forces already stationed in Italy and reinforcements from Illyricum and Epirus were primarily responsible for confronting the invaders: by the time the troops from Spain and Gaul arrived, the entire southern branch of the invaders had been killed or captured. One of the generals stationed in Italy, Marcus Aurelius Probus, declared himself Emperor on October 4; stating that his leadership in dealing with the invaders had proved him to be truly deserving of the purple, and that the course of the war had proved Aurelian unworthy. Just two days later, the governor of Macedonia, who had not heard the announcement yet, also declared himself Emperor.

The initial success of the Germanic invasion was a second blow for Aurelian. It also gave the Macedonian usurper a chance to prove his worthiness of the purple. He made fairly good use of that opportunity by slowing down the progress of the Germanic invaders.

The Downfall of Aurelian
Meanwhile, Aurelian's campaign in Gaul was progressing slowly. Ever since the war began, many Gallic, Spanish, and Britannian civilians had volunteered to fight for Postumus, and the effects this swell in the size of Postumus' military were clear. Postumus had more troops to defend Colonia Agrippina with. Meanwhile, Aurelian's soldiers and officers had steadily become dissatisfied since they had heard of the attacks in Italy.

The last straw came toward the end of 275. A large number of Spanish and Britannian units had quietly made their way to southern Spain during October. When they arrived, they began coordinating with local resistance cells that had been created during the spring and summer. The plan was for the outside forces to invade the areas controlled by Aurelian's forces on four fronts, two land and two naval, while the locals would stage uprisings in towns and cities near the locations of the invasions as well as several major cities in the interior of the occupied territory. All parties were to begin well before dawn on November 24. The plan was largely successful. The external attack on the eastern land front found itself bogged down, and some of the internal uprisings were quelled, but Aurelian's forces had lost much of the territory in Spain that they had still controlled within just a week. By the middle of December, forces loyal to Postumus had retaken all of Spain.

Aurelian's senior staff in Gaul had already been considering whether to kill him and set up a new Emperor. As soon as they learned that the forces in Spain were rapidly losing, they decided that they could no longer tolerate Aurelian. They also decided that he deserved worse than to simply be assassinated. On December 27, 275, while Aurelian was sleeping, soldiers loyal to Aurelian's senior staff overwhelmed Aurelian's bodyguards, entered his tent, broke all four of his limbs, and then dragged him into a cage. At dawn, he was presented to his forces, at which point one of his generals declared himself the new Roman Emperor and declared that Aurelian had been deposed. This third usurper declared that his first act would be to pull out of Gaul.

The Gallic Declaration of Independence
Up until this point, while Postumus had on the one hand refused to recognize the authority of the official Roman Emperors, and on the other hand made no effort to take over the entire Roman Empire; he had never actually declared his territory to be seperate from Rome. This changed on January 14, 276, when Postumus issued the Declaration of the Independence of Gaul, Spain, Britannia, Raetia, and Transpadana from the Roman Empire, which would be known commonly as the Gallic Declaration of Independence. The document declared these lands to constitute the Roman Empire of Gaul, which would be informally called the Gallic Empire.

The reasons stated in the Declaration for the Gallic Empire's secession were largely based on a "Two Romes" theory that had become popular among the people, although never endorsed by Postumus up until this point. According to the Two Romes Theory, the Gallic Empire had emerged as an internally stable and increasingly prosperous New Rome; whereas the remainder of the Roman Empire's territory constituted the Old Rome, which was still tormented by civil war, barbarian invasions, and economic hardships. The Declaration cited various successes of Potumus, various generals and provincial governors, and the people; as well as various failures of the Emperors and institutions of the Old Rome. Also, the Declaration stated that the Gallic Empire owed the Old Rome and its Emperors nothing, that the war had proven that the Gallic Empire was sustainable, and that reunification of the Gallic Empire with the Old Rome would be harmful to territories belonging to the Gallic Empire and not particularly beneficial to the Old Rome.

New Problems for the Gallic Empire
By February, the last of the Roman troops had withdrawn from Gallic territory. Throughout January, the Gallic people celebrated. Unfortunately, it soon turned out that the war with the Roman Empire was not over yet. The Germanic invaders in Pannonia and Noricum had gotten nowhere since November, and now the Alamanni and Quadi had sent envoys to Colonia Agrippina demanding that Postumus send troops to their aid. On January 28, Postumus chose to aid the tribes he had made the alliance with.

When the alliance with the Alamanni, Marcomanni, and Quadi was first made, some people had disapproved, but the alliance was generally accepted. When Postumus made the alliance, he had counted on the Roman invasion of the Gallic Empire persisting for at least a few months longer than it did, and he had also underestimated the strength of the forces in the eastern part of the Roman Empire. He had garnered support for the alliance among the Gallic people and military by presenting it as a way to further weaken the Roman Empire and a way to give the Alamanni an incentive not to invade the Rhine frontier. Neither Postumus nor the majority of his generals foresaw that Gallic troops would have to actively aid their allies.

Postumus' decision to send troops to help out the Germanic tribes was not well received by the people. Only a few weeks before, it seemed like the war was over. Many people wanted the newly independent empire's resources to be devoted to rebuilding cities and towns that had been damaged in the war. Others assumed that the problem would resolve itself, either by the three claimants to the Roman throne turning on each other and neglecting Pannonia and Noricum, other Germanic tribes entering the fray, Persia taking advantage of the general state of disorder, or some combination of these. Of course, the people who had opposed the alliance to begin with were angrier than before. The intervention had more support among the higher-ranking officers and in the Gallic Senate, but that support was a reluctant support, and there were many in those circles who disapproved.

On February 12, a moderately important Senator called for the deposition of Postumus. The proposal failed: on February 16, the majority of the Senators voted against considering possible replacements for Postumus; although the next day, the Senate did issue an official statement condemning Postumus' decision to send troops into Pannonia and Noricum.