Why did the oval shield replace the scutum?

[Sean Manning]

Robert, I agree that there are large differences between a Roman phalanx in 400 CE and a Greek one in 400 BCE, but I still think its best to see them as examples of one phenomenon. Although my Greek is still so-so, I think that when ancient Greeks speak of τινα φάλαγξ they usually just mean a continuous battle line of men in close formation several ranks deep. Three phalanxes one behind the other are still three phalanxes, and classical Greek hoplites had psiloi to keep shooting and throwing over their heads once they came into contact.

I agree that there are a lot of things we don't know about classical Greek phalanxes ... but Xenophon seemed to believe that a Greek phalanx of doruphoroi, an Egyptian phalanx with body shields and very long spears, and an imaginary Persian phalanx with sagareis and mikra gerra differed more in details than in essence. I take his judgement in res militares quite seriously.

Although I believe this is stretching the limits of the topic quite a bit (maybe I should open a thread about it?), did Xenophon say the Persians used axes&taka? I mean, unless the taka were large, they would no fit a phalanx. Also, the spear was the weapon of honor in Persia, not the axe.

Xenophon repeatedly tells in the Cyropaedia (eg. 4.2.22) that his fictional Persians were armed with gerron, thorax, and either sagaris (an Iranian or Scythian axe) or machaira (a chopping sword). They fought in ranks and files with about a square yard of space per man. I believe that the military scenes in the Cyropaedia are supposed to instruct Greek readers, so clearly he believed that men armed "like the Persians in pictures" could behave similarly to Greek hoplites. Whether his fictional armament was ever seen in real life is another question!

I think of all the changes in Roman military equipment over the ages, this one has intrigued me the most, probably because it affects directly my 'period-of-choice', the Third Century.

What do we know of the development of vertical grip shields anyways? Connolly shows surviving La Tene period scuta as flat with a horizontal grip. I have a vague idea that flat vertical grip shields are 'Germanic' but I would like to learn more about when and where they appeared.

The late shields were vertical grip?[/quote]
Well, I know that early medieval shields, such as the Norse used, had vertical grips, and this tradition continued until target and buckler fell out of use in the 18th century. I don't know a lot about late antique warfare but there had to be a transition at some point!