Thread by @StilichoReads

One of the commonly given causes of the fall of the Western Roman Empire is the barbarianization of its army - the army was increasingly made up of foreign Germanic tribesmen, with a corresponding decrease in loyalty and effectiveness. Was this true? A thread:

It isn't really in doubt that the Roman Army was increasingly made up of ethnic Germans, both recruited individually into professional field army units and incorporated as whole tribes of Foedreti. Still, the majority of soldiers were probably born within the empire.

An analysis of soldiers mentioned in sources found that 52% were born in Gaul and Illyricum, and only about 25% were born outside the empire's borders. However, they appear to have been more numerous in the most elite units, and this was still an increase over the early empire.

Interestingly, the Army's culture Germanized as well - even non-German soldiers increasingly dressed and spoke like barbarians. Soldiers wore pants and gold torcs, had long hair, and used Germanic words like fulcum (shield-wall, from "folc") and barritus (war cry).

It would have been difficult for the Roman urban elite to tell the difference between a Gothic warrior and a Roman soldier, even one who was ethnically Gallo-Roman, Illyrian, etc. There was a common frontier/army/Germanic culture that most professional soldiers shared.

If the Roman army was definitely Germanized, was it also degraded - less loyal and less effective on the battlefield? No - it remained a high quality force right up to the end, and beyond in the Eastern army.

The idea that it was has a long pedigree. It goes back to Rome itself, and the book De Re Militari (On Military Matters) by Vegetius, which said that the soldiers of his time (the early 400s) were less disciplined and physically weaker and shorter than they were in early empire.

We if Vegetius was a soldier - we don't know anything about him other than that he was a Christian and that he also wrote a work on veterinary medicine. Wherever he got his information, it goes against the actual narratives of battles and campaigns that survive.

Ammianus Marcellinus, an army officer and imperial bodyguard, wrote a history covering the period 353-378, including numerous detailed battle narratives. The Roman infantry is consistently excellent.

At the Battle of Strasbourg (357), the Alamanni broke through the front line of the Roman Army, but the now-divided soldiers held their formation while the reserves stopped the Germanic advance and than moved up to plug up the hole.

During the Siege of Amida by the Persians (359), the heavily outnumbered Roman defenders launched a night attack on their besiegers, and inflicted heavy casualties before reforming and fighting their way back into the city's walls.

Even at the famous Roman defeat at Adrianople (378), the Roman infantry fought on for an extended period after being outflanked, and, after retreating, reformed under the walls of the city of Adrianople and held off an attack on the city itself.

These are only a few examples, but they paint a picture of a force that was both cohesive and tactically effective. We don't really have this kind of detailed source for the period afterwards, but what we do have suggests that Roman field armies won most of their battles.

If this was the case, how did they ultimately collapse? First, the most common enemy for a Roman army was another Roman army. Second, while the Romans hadn't gotten worse, their opponents had gotten better in organization, tactics, and equipment - but that's for another thread.

My main sources for this thread:

https://twitter.com/StilichoReads/status/1444048406805053442?s=19