Late antiquity engendered consequential institutional adjustments for Roman arms. The wealth of the state meant that Rome would always attract the best recruits to its standard, but commonly these recruits were foreign mercenaries. Although still effective the army over time became more and more challenging to control because of foreign preeminence.
The Western Roman Empire never solved the problem of the barbarianization of its army, but rather was taken over by it, and collapsed as a state in 476. On the other hand, the Eastern Roman Empire answered the institutional dilemma of barbarianization first by elevating the hard-bitten Isaurian Romans of Anatolia to supremacy over the formerly favored barbarian mercenaries, and later by establishing the militia thémata system.
The late Roman writer Vegetius sought to unravel the institutional riddle of the late Roman army by advancing the thesis of how the ideal Roman army ought to be organized. His work never reflected the reality of late antiquity, but would become influential in the medieval West.
“Victory in war does not depend entirely upon numbers or mere courage; only skill and discipline will insure it.
“Recruits in particular should be obliged frequently to carry a weight of not less than sixty pounds (exclusive of their arms), and to march with it in the ranks. This is because on difficult expeditions they often find themselves under the necessity of carrying their provisions as well as their arms.
“The courage of a soldier is heightened by his knowledge of his profession, and he only wants an opportunity to execute what he is convinced he has been perfectly taught. A handful of men, inured to war, proceed to certain victory, while on the contrary numerous armies of raw and undisciplined troops are but multitudes of men dragged to slaughter.
“Troops, defenseless and exposed to all the weapons of the enemy, are more disposed to fly than fight.
“To pretend to enumerate the different nations so formidable of old, all which now are subject to the Romans, would be tedious. But the security established by long peace has altered their dispositions, drawn them off from military to civil pursuits and infused into them a love of idleness and ease. Hence a relaxation of military discipline insensibly ensued, then a neglect of it, and it sunk at last into entire oblivion.
*All excerpts have been taken from Military Institutions of the Romans, Praetorian Press, LLC.