Goffredo wrote:That the gladius was intrinsically too short cann't be the answer as the romans fought against long sword gauls for centuries!
I wrote short in relation to cavalry opponents. Since more and more enemies of the Empire had cavalry (and more of it), I suggested that maybe (just maybe) this could have been a factor in the need for a longer sword, next to the need for a longer spear.
Goffredo wrote:Is it a "fact" that the gladius and pilum went out together along with old the old cylindrical scutum? I am not an expert enough, but I do believe that by the end of the 2nd century things had evolved and the traditional legionary equipment may have been slowly phased out. By the end of the 3rd century even the legion was phased out.
They were phased out, but we have by no means any solid information which went when. In my book, there was no centralised 're-arming plan' or something like that. I do think that tactics changed and with it, training and armament. But I don't believe in a general order from Rome (or wherever) to the armies that they should discard this or that item.
Scuta, for instance - we see the old rectangular shield in Dura Europos.
The old helmet (Niedermörmter) on the other hand was already in disrepute (because it was too large and encumbering) even before Septimus Severus attacked Persia, which we know from Julius Africanus.
We have no idea when exactly the gladius went, or when the semispatha was dveloped.
We also have no idea when the pilum went, although I would tie that to the advance of the hasta. maybe the plumbata marks the end of the pilum, but them (apart from Georgia) I know of no find of plumbatae in the Middle East. Also remember that whereas the Roman pilum went out, the Germans copied it in the
angon - a highly prized weapon!
Goffredo wrote:Everyone realized, germanics especially, that set battles against a well balanced roman army was in rome's favor. Even when roman's resumed aggressive campaigning against germanics beyond limes they did not fight large set battles as the enemy did not offer such occasions. (Think twice of Arminius).
Not just Arminius. Gregory of Tours quotes Frigeridus' lost works about Late Romans under Arbogast being ambushed in a wintry forest east of the Rhine... Indeed, set battles were in favour of Roman troops, mostly, and hence German forces raided and ambushed more.
Goffredo wrote: Think of long wars during Marcus' reign where vexillations were normal practice. Evidently over 150 years a pattern had slowly but surely been set and by Marcus' time wars in the north were quite different than they were during Ceasar's time and Trajan.
Vexillations became the norm, I think from the Late 3rd c. onwards. I should read a bit about that, but that seems to have happened during Diocletian's or Constantine's army reforms. We see the classic legions then being split up into smaller units (some early, some later).
NB: these, too, resemble the old independeny auxilia cohorts of 500-1000 men...
Goffredo wrote: But even in these battles mobility was more important that brute force (roman armies did not need to annihilate the other roman army!).
No, we see indded that Roman armies tended to kill their commanders, usurpers or emperors, when they thought the other candidate was stronger. they then defected and were received by the other usurper or emperor without much of a problem.
Goffredo wrote:the real impetus for cavalry came from fighting other roman armies.
Why would that be so?
Goffredo wrote:So by the end of the 2nd century the heavy infantry legion was rarely deployed whole, instead detachments were expected to be sufficient for almost all types of operations.
I would not use the word 'sufficient' here. With all the usurpers and counter-usurpers all over the empire (and barbarians running loose inbetween), legions were under an enormous pressure, shoring up one sector after another. I think they were constantly asked to send vexillations to this sector in danger and that emperor fighting another. Most classic legions, once a proud 5000+ strong, must have been way below that strenght, halved or even less. To me, this is the basis for the model of the 4th c. army, the real end of the legion.