[split] Distances between files and ranks

[Nathan Ross]

Tacitus (The Annals 1 51)

This passage just says that Germanicus split his army into four columns to ravage the enemy country. He then made his return march in what appears to be agmen quadratum formation (although T doesn't refer to it as such) 'prepared both to march and to fight'. There's nothing here about the width of the columns or the depth of the battle formations, which is what we were discussing. What else are you seeing here?

It was simple, extremely simply. But to do it, the army had to halt, to do the last manoeuvre. Until that point, it would be the same as Polybius (achieving battle order in one movement).

Yes, that sounds pretty simple to me too. What's the difficulty?

you have said nothing on my legion of 12 deep changing to 8 deep.

You mean the thing about the pilani not being with the legion, or something? I didn't really understand that part, I'm afraid. Do you mean that Arrian's 8-deep formation is missing four extra men in depth, because those men are 'pilani' and are away guarding the camp? So his formation should be twelve deep?

If so, what do other twelve-deep formations do about guarding the camp? And why would you need a full third of your soldiers to guard the camp anyway?


Meanwhile, going back to Deryk's original post (which was actually about the deployment of Suetonius Paulinus against Boudica in AD61):

some anomalies regarding the distances between the legionaries especially if they were 8 deep... Firstly when the pilums were thrown there would have to have been 3 foot between each man to allow for the throw therefore they couldn't have been in close order at that time.

I was looking again at Arrian's Against the Alans; this is the most detailed account we have of a battlefield formation of a date reasonably close to AD61.

Section II, about the march, is very clear that the entire infantry contingent moves in fours: "The formation should be four soldiers wide... foot soldiers should be drawn up in fours... This legion should also be drawn up in fours."

In Section VII, we have the deployment: "They should deploy in eight ranks and their deployment should be close ordered. And the front four ranks of the formation must be of spearmen, whose spearpoints end in thin iron shanks... Those standing in second, third and fourth rank of the formation must hold their spears ready for thrusting... The following ranks should be of the javelineers. The ninth rank behind them should be the foot archers."

In Section IX, we have the tactics: "the first three ranks should lock their shields and press their shoulders and receive the charge as strongly as possible in the most closely ordered formation bound together in the strongest manner. The fourth rank will throw their javelins overhead and the first rank will stab at them and their horses with their spears without pause."

So a four-abreast march deploys as an eight deep close-order formation, with a single line of archers at the rear. This sounds to me like a 80-man 'Hyginian' century arrangement, with the legion drawn up in two lines of centuries, each century 20 men x 4 men.

The most important thing is that the first three ranks have to be close enough together that they can lock shields to repel cavalry. And note that Arrian only has the fourth rank thowing javelins, over the heads of the men in front; all these men, I would suggest, have been trained to work together in formation. He doesn't tell us what ranks 5-8 are doing!

So we could have the forward century in four close ranks, then a slight gap, then the rear century also in four ranks, to make up Arrian's array.