Dr. Bret Devereaux

That is a thing you do when someone's going to be shooting down at you from like a wall.

It's not a thing you do in an open battle, whatever gladiator told you.

At least not an open battle that's going well.

If you're forming Testudo, it's because somebody is plinking at you and you have no hope of getting into contact with them.

And also, you're at car eye and you're all screwed up.

Okay.

So what you should understand here, right, is the front rank, these guys have their shields maybe close to touching, maybe just barely touching, maybe slightly overlapped, but probably not.

not shoulder to shoulder, there's some space in that rank, and then there's probably a couple feet, and then the next rank is formed up the same way, so that if somebody falls in front of them, the next guy steps up.

And you can see how you could bend the flanks back to make this kind of a crescent.

Bending it all the way back to make a circle would be tricky, tactically tricky, but not insane.

Tolkien may be thinking, of course, of, you know, bayonet and musket armies forming square,

under battlefield conditions.

Or he may be thinking of in Scotland and parts of Northern England, the Schiltromm, which is a circular formation of pikes and spears and shields all facing outward.

And a similar sort of, you can't flank me because I don't have a flank kind of formation.

Always the danger of those kinds of, I don't have a flank formations is that they tend to get packed in pretty tight.

And if your opponent can plink at you with something,

You could be in trouble, whether that's with longbows, which is what the English would sometimes use to break up the Schiltron, although it didn't always work great.

Scots do occasionally win.

Or in the early modern period, the correct response to enemy infantry forming a square was to blow the heck out of them with cannon.

Ah, cannon, yeah.