Re: Fine Shields
 

The Roman scutum has a center grip rather than a strap.

This is why it has to be curved. You can't hold such a long shield at arm's length in the enemy's face for any amount of time so you need it to curve around the body as you hold it close.

But of course this won't work at all on horseback, hence the strapped Norman flat shield.

Re: Fine Shields
 

I've seen them with and without straps; it's possible that the strap is simply for carrying it around, but some of the strap arrangements make it look very much like a guige - designed to help support the weight of the shield with the back and shoulders.

It is possible that that arrangement is ahistorical; I'm looking for sources.

The grip is also horizontal, which is interesting.

The aspis is the classic giant, heavy Greek shield...and huh. That one seems to more or less strap to the forearm just below the elbow, is deeply domed (you can rest the upper lip on the shoulder), and what I thought was a shield strap was actually a sword baldric hanger.

Re: Fine Shields
 

A visual comparison of center grip vs strapped is on the front cover of ITL