When did the Roman Army lose it\'s...

[Robert Vermaat]

When did the Roman army, in your opinion lose it's strength, discipline, tactics, excellent leadership, and overall superiority that had made it the effective and superior fighting force that it had been for centuries.

Never. Ah well, maybe that's overstating it, but apart from that last one, I'd say until Manzikirt in 1071, after which the Roman Empire for a great deal had to rely on foreign forces.

A lot of documentaries say that the Late Roman Empire (284-476) became more and more built from Germanic mercenaries and what have you, is this when they lost their effective superiority that had made them the army that carved out the empire of the known world?

Yeah, well, that says more about those documentaries, doesn't it? Go to any period of weakness in any empire, take one aspect and blame it on that, and there you have it. So the answer would be 'no'.

This has been discussed before, you know.. Just a few I could find:
http://www.ancient-warfare.org/rat.html?...3743#33756
http://www.ancient-warfare.org/rat.html?...3419#33425
http://www.ancient-warfare.org/rat.html?...979#157670
http://www.ancient-warfare.org/rat.html?...195#223246
http://www.ancient-warfare.org/rat.html?...268#198268
http://www.ancient-warfare.org/rat.html?...936#265977
http://www.ancient-warfare.org/rat.html?...&id=216699

First of all, it's of course only the West that was lost in the period you're discussing, the East managed to hang on, re-expand etc. for centuries after the 5th c., with excellent armies.
Secondly, it's that focus on the high tide of the legions of the 2nd c. and take that force as the 'superior fighting force'. I can tell you that, as a fighting force, the Roman army of the 5th century was not different from that of Ceasar's legions, or that of Trajan. The problem is more that circumstances differed hugely. Far stronger enemies for one, or a lack of troops for another. Armies of the 2nd century could also be wiped out when circumstances were against them, only there were enough troops to make up for those losses. Especially during the 5th c. in the West, this was not the case. Economic circumstances and political mayhem in the Empoire caused the army to melt away.