When did the Roman Empire fall (your thoughts)?

[Robert Vermaat]

Even worse, using mercenary or "federate" troops meant relying on untrustworthy elements for the bulk of combat power. I think that Roman commanders would've preferred to have an army of citizen soldiers. They had to have, or tolerate mercenaries and "federates" because lack of enough citizen recruits left them with no choice. By or after 408, the only way to fight one barbarian group was to hire another.

@ untrustworthy or not, it seems that politics meant that you could do worse than mercenaries: a Roman commander could be betrayed by other Roman armies who did not turn up to help (Julian fought alone at Argentorate) whereas federates did what they were hired to do (the Goths at Frigidus).

@ 408: how do you know that? We simply do not have enough sources to know that. After 430 or so maybe, but 408 is too early I think. Romans of course hired troops all over the place, but that could also be strategy: let barbarians fight each other.