1 roman legion consists of how many troops?

Question

why are the romans defaeted by the barbarians even they are more disciplined and well trained

Answer 1

Nobody answered the second part of your question. The Romans troops who faced the barbarians were not the professionals under Gaius Marius and Julius Caesar (particularly his 10 Legion), but they were trained from youth for war. In later years of the empire, Rome employed 'civilized' barbarians as mercenaries and indeed as Roman citizens.

A Roman army in later times was composed more and more of conscripts and barbarian mercenaries. Roman were an occupation army no longer fighting wars of conquest. There were always battle-hardened veterans mixed in. But as you can imagine, the barbarians took advantage of a weaker foe, not to mention the civil war politics back home....Rome was no match for the barbarian horsement.....all led to barbarian victories in Gaul and Italy itself.

Answer 2

6000 in a legion, or 10 cohorts (early)
Later, legions were limited to 1000 to avoid giving a field commander too much strength to mutiny.

http://infotech.fanshawec.on.ca/faculty/newell/legion.htm

As for why the roman empire fell, it's a complex question that historians still debate. To get some insight on a specific occasion when barbarian troops defeated roman troops in battle, you should look up that battle. (Adrianople, for example)

Answer 3

5000 men 100 horses 25 chariots and 2 catapults 600 servants traveled with the army to see to its needs .