Benjamin Parker wrote:It shows the manica on Trajans column also they added greaves to their armament and crossbars to their helmets but how would a cutting weapon get through a helmet?
It probably didn't. Note how I said that current theories about the falx usually emphasize its effectiveness against
unarmored flesh, and the theory about the origins of the manica takes this a bit further by positing that Trajan's legionaries adopted the manica because they had seen the effects of the falx upon unprotected flesh and believed (probably quite correctly) that metal limb defenses like the manica and the ocrea (greaves) would give them adequate protection. Of course, this theory is currently in dispute, since there's some evidence about the use of the manica by Roman legionaries and their opponents (revolting gladiators, in this case) well before the Dacian campaign--it's all summarized in this page:
http://www.romanarmy.net/manica.htm
but of course this new evidence doesn't rule out the possibility that Trajan's legionaries
did specifically adopt the manica to defend against the falx; it only makes it more likely that the legionaries were simply following a precedent shown by the effectiveness of the manicae worn by earlier legionaries.
As for the Bruce's axe, there are three excerpts from translated primary sources available online via De Re Militari:
The Scalacronica
The Lanercost chronicle
Vita Edwardi Secundi
Two out of the three excerpts mention that the Bruce killed Henry de Bohun, but nothing about cleaving the knight from crest to chin (
not to the navel), so I still don't know where the "crest to chin" story came from--probably from a different chronicle, or a section of the Scalacronica outside the excerpt. In any case, I recall reading that the "crest to chin" trope came up only in
one chronicle--not any of the others--and so it might just be a dramatic exaggeration rather than a representation of the truth, since the other chronicles would probably have remarked on the "crest to chin" cut as well if it had actually happene.