Roman Legion in late Antiquity

[sonic]

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Finally, the economic problems of the third century onwards demanded that the army change to armour and equipment that was cheaper to make and almost, if not as, effective as earlier styles. The change in equipment may have forced a change in tactics and hence a change in unit structure in different parts of the Empire......

Spears, swords, shields, armour, heavy throwing weapons, light throwing weapons and bows.....

Changes were minor, refinements happened, economics played a part - but nothing really changed in well over 1,000 years. The medieval period eventually saw extremes of plate armour and longbows, but there was no overriding need to change tactics and therefore battlefield organisations until gunpowder - and not much needed then (a Napoleonic French Corp at Waterloo (now including guns) is almost identical to a Polybian Consular army). Only with the advent of rapid-firing machine-guns, modern artillery and tanks did the next revolution in warfare occur.

I couldn't disagree with you more. Changes in the attitude of the Roman army and the way that army was used changed dramatically between the first and the fourth centuries AD. To base the miltary culture of the different political entities of the first half of the first millenium solely on the basis of the equipment which they used flies against all of the research and conclusions reached by military historians since Keegan's 'Face of War'. If you don't believe that culture had a major part to play in warfare, consider this.

At the Siege of Masada in AD 73 the Romans amassed c.15,000 troops to take a fortress manned by less than 1,000 zealots. After a 2 month siege the citadel was captured by assault, despite the fact that the Romans expected to suffer heavy casualties. In the fourth century AD the future emperor Julian surrounded 600 barbarian raiders in an old, disused fort and starved them out rather than risk heavy losses.

I believe that the change in tactics and strategy from offensive to defensive warfare played a major part in the reforms of the fourth century, based both on the change to defence and the focus changing from attacking Rome's enemies to defending against internal rebellion and not incurring large numbers of casualties on the army. Whereas earlier at the first sign of trouble the old, large legions would be led out to attack the enemies' homes, later the priority became small units spread around the empire, capable only of self defence unless led by a capable military leader, usually the Emperor or a Caesar. In this way the Empire was defended and the threat of revolt (theoretically) minimized.