Hello everyone , sorry to dig up this old tread .
so if i understand square shield was optimum for manipular formation with pilum and gladius
then rounded scutum appeared to be used with longer spear
And round shield like parma or viking shield were perhaps with vertical grip to be used with spata swords and more mobile and individual combat ?
have a good day cheers ^^
Alexis
No, this is just conjectural. Most people think that the rectangular shield was omnipresent for a longer period, but archaeological evidence as well as pictorial evidence do not support this assumption. This assumption mostly exists because TrajanĀ“s Column is overrepresented in the discourse. It rather appears that oval shields were the the whole time, starting from the early republic up to late antiquity, and that for a while rectangular shields were in use also. But it seems that the rectangular shields were never used exclusively by the Roman army.
A rectangular scutum is a bit more protective, especially on the upper side, as the corners add more coverage. It is also a bit more protective and easier to use when forming a shield wall and testudo. Its also easier to construct, as pre-measured strips of wood can be used can be laminated together with glue without an further cutting, other than the hole for the center grip. The shield edging is easier to make, being straight.
With an oval scutum or clipeus a slashing move of a sword is a bit easier as the missing corners facilitate diagonal movements. Also, the bottom edge of the shield is more suitable to being used offensively with a horizontal shield strike. A bit harder to make as it adds the steps of having to cut the curvature and the shield edging is harder to make and must be personalized to shield.
In the history of the Roman shield, they went from being oval and curved, to semi-rectangular and curved, to rectangular and curved, to oval and flat or dished, over the course of hundreds of years. In the meantime, individual fighting tactics didn't seem to change much, though swords changed a bit (blades shrunk and then lengthened).