In 395 AD, after the battle of the Frigidus River, Theodosius was emperor over a united Roman Empire. Its extent was virtually the same as it was at the time of Trajan, the golden age But less than a century later, a Germanic officer sent the regalia of the Western Emperor back to the East, saying that it was no longer required.
What had gone wrong?
If you measure by military power the West had traditionally been stronger than the East. Time after time in civil wars the western claimant had beaten the eastern one, in fact I can’t think of an exception – except Theodosius himself. And even in his case a rightful emperor fighting a usurper needed a windstorm to turn the tide of battle in his favor.
And the situation didn’t change after 395. The Western armies had some failures and successes contesting with the barbarians, but the East was pretty much helpless in the field against them during the entire period. But the Eastern Empire had Constantinople, and could thus avoid a field battle.
The West could not, because the fortified cities it had were not shielding the rest of the country, but were shielded by it. If a Western Roman army retired to a major city, the land and crops and wealth of the entire country were exposed and helpless. The East could always rely on Anatolia to be safe if the Balkans were attacked, and for the Balkans to be safe if invaders came from the East.
Geographically the Western Empire was all border, and virtually no heartland. This meant that defense was expensive, relative to the population.. And if the defense failed, the invaders were almost at once in a position to cut major links that the defenders would need to rally and recover. A breakthrough in Illyria cuts Greece from Italy. It’s not far from the German border to block the Alpine passes between Italy and Gaul and the roads to Spain.
With the technology of the time, water transport on the Mediterranean Sea was unreliable for much of the year, so there was no compensating advantage for the replacement of potential interior provinces by water.
The FIRST Cracks in the DAM
The arrival of the Huns in Europe around 400 caused a major dislocation across the frontiers. The West, whose generalissmo Stilicho was dealing with an on-again, off-again contest with Alaric and the Visigoths at the time, suddenly was faced with a major disaster. A second force of Goths, under Radagast, and the Vandals, Alans, and Suevi nations crashed across the border not looking for loot, but for a place far from the Huns.
Forced to choose one, Stilicho chose to fight Radagast’s force, and defeated it, taking the survivors into the army. But this gave the Vandals a free hand, and they were allowed to ravage Gaul unhindered.
Time out for treachery
Stilicho was trying to come to an accomodation with Alaric, but this negotiation with the Goths did not sit well with everyone. At this time, the Emperor turned on him and had him executed. On hearing this, the cities of Italy turned on Goths living among them and massacred them. Many of these were the families of the Gothic soldiers in the army, including the new recruits from Radagast’s force. With no hostages, and a lot of resentment, they defected en-masse to the nearest Gothic force – Alaric.
So instead of having an alliance with the Goths and a competent general and a large army, the West now had no army, no general, and an angry force of Goths on the border. And still, nothing was done about the Vandals in Gaul.
WHAT about the Vandals?
With no resoponse from the central government, local forces began to move. In Brittania, there rose a rival Emperor who took the forces in that province, and those on the Rhine, and started to pressure the Vandals. He couldn’t defeat them, but he did pressure them and at long last they started to retire from Gaul into Spain. Of course, this meant Rome now had a civil war to fight, if they could fight anyone.
what about the goths?
What Alaric really wanted at this point was to join the Empire, not beat it. But the new anti-Goth posture made that a problem. For some time he used the threat of an attack on Rome to try and force the Emperor, safe behind fortifications at Ravenna, to deal with him. But the Emperor Honorius would not. It looked like the refusal to deal was working until someone opened the gates of Rome and let the Goths in in 410 AD. The Sack of Rome followed, and Alaric at least had some spoils to justify the time he had spent. Alaric died soon after this, and his successor threw in the towel and moved into Gaul to find a place to settle, just like the Vandals, Alans, and Suevi.
Even the sack of Rome wasn’t the end of the empire. Brittania was abandoned, there was a civil war to fight in Gaul, and the occupying barbarians to subdue. But Italy was free and Africa was untouched, so there were resources to make a comeback. Under a new general the rival Emperor was defeated, and most of Gaul recovered. A deal with the Goths was made to hire troops to press the barbarians in Spain. By the Early 420s the Alans were crushed, and the Vandals and Suevi restriced to isolated parts of Spain.
Emperor Honorius again decided to do without his general, and the pressure relaxed. Honorius’ death left a power vacuum that led to a dreary struggle for control of the Empire that took up all the time and resouces, allowing Spain to fall back into the barbarian’s hands.
The Vandals used this time wisely. in 429 they transfered their entire people into Africa, and relentlessly moved towards the richer provinces around Carthage. Roman responses were limited by the power struggle and the difficulty of supporting a naval invasion. During the next decade the safest and richest province fell, and was soon supporting massive raids of Gothic pirates on the remnants of the Empire, including a week-long sack of Rome.
nowhere to run
After this the pattern was set. An attempt to settle the Vandals would be interrupted by trouble elsewere – like the Attila’s two invasions of the Empire. Efforts to gain the upper hand in Gaul would be folied by Vandal raids. Even the dissolution of the Huns gave no relief – the barbarian states that rose afterward moved into the undefended Balkans and removed them from the Roman orbit.
With no provinces to tax and no troops to purchase, the reach of Rome lessened until they were fighing just outside the bounds of Italy. At this point, the barbarian general leading the winner in the latest civil war called a halt to the farce and declared the Empire over.
The weakness of the Western Empire was its fragility. Rather than a compact defensive circle, it was dispersed. Once the shell was broken, they were in serious trouble, as the Empire was not that much stronger than the barbarians. Without a brilliant leader, or an accession of strength, they were caught on a downward spiral where they lost power faster than their rivals.
It makes you wonder if cutting a deal with Alaric might have put them over the top. On the one hand, he might have taken out the empire 50 years earlier, but if they had been able to assimilate the Goths instead of having to fight them during the generation of the 430s, they might have been able to avoid the loss of Africa and carry on from there.