05-02-2013, 08:36 AM
In regard to the battle of Mons Graupius, I am puzzled by the division among historians concerning the number of reserve cavalry used by Agricola to attack the Caledonians in the flank and rear. One school has the reserve cavalry at four squadrons and the other school at four alae. Looking at the Loeb edition I have available it reads “Agricola quatuor equitum alas;” and is translated as four squadrons of cavalry. But my Cassell’s Latin dictionary has equitum as meaning either a turma or ala. From this I gather the difference between four squadrons and four alae is the historian’s personal choice? Am I right in thinking this way?
Four squadrons number 120 men and four alae around 2000 men. If the Caledonians were trying to outflank the Romans on both Roman flanks (left and right), this would allocate two squadrons to attack each Caledonian flank or two alae per Caledonian flank. If the Roman reserve cavalry was only attacking one Caledonian flank I still think four squadrons is too small, whereas four alae would do the job.
The account by Tacitus highlights there was a debate between the staff officers and Agricola about the Roman deployment with the staff officers wanting to deploy the legions in the same line as the auxiliary infantry. Agricola is against this and my translation of Tacitus believes Agricola’s deployment would be disproportionate. I have interpreted this to mean one of the lines, either the legions or the auxiliary infantry will be shorter or longer than the other line. What I have found is the deployment system used by the Romans is based on the frontage of a legion in its standard deployment. This means the Romans have calculated how many cavalry squadrons can fit within the frontage of a legion. For example, at Cannae Paullus would know that the frontage of his army both infantry and cavalry was equivalent to 36 legions. By doubling his depth, the frontage would be equivalent to 18 legions. It’s actually a square measuring system and is simple and very effective. So theoretically a commander can assign those units in a square different deployment arrangements, or even have one unit cover two squares if need be. This system can tell what the standard frontage and depth of a cavalry squadron should be. I’ve applied the Roman deployment system to the 8000 auxiliary infantry at Mons Graupius and it strongly points towards them belonging to cohors equitata miliariae. This means a large part of the 3000 cavalry also belong to those auxiliary cohors equitata miliariae.
The deployment arrangement I have ended up with has two lines, the second line consists of two legions each flanked by two alae and the remainder of the cavalry are deployed on the flanks of the auxiliary infantry. I believe the cavalry deployed on the flanks of the auxiliary infantry are the ones mentioned frontally attacking the Caledonians. Even with the auxiliary infantry extended, the auxiliary line has a shorter frontage than the second line. As the staff officers wanted to deploy the legions with the auxiliary infantry this indicates the depth must be the same as the auxiliary infantry and this rules out the legions being core legions (not full legions). From this I believe Agricola wanted his first line to be shorter in order to tempt the Caledonian reserve sections to come down the hill and attack the first line in the flank.
If I reverse this deployment and have only four squadrons in reserve it just looks wrong as the strike power is extremely whimsical, plus the Romans have too much cavalry in the first line. However, if it can be proven to me that “quatuor equitum” does categorically mean squadron then its back to the drawing board for me.
Four squadrons number 120 men and four alae around 2000 men. If the Caledonians were trying to outflank the Romans on both Roman flanks (left and right), this would allocate two squadrons to attack each Caledonian flank or two alae per Caledonian flank. If the Roman reserve cavalry was only attacking one Caledonian flank I still think four squadrons is too small, whereas four alae would do the job.
The account by Tacitus highlights there was a debate between the staff officers and Agricola about the Roman deployment with the staff officers wanting to deploy the legions in the same line as the auxiliary infantry. Agricola is against this and my translation of Tacitus believes Agricola’s deployment would be disproportionate. I have interpreted this to mean one of the lines, either the legions or the auxiliary infantry will be shorter or longer than the other line. What I have found is the deployment system used by the Romans is based on the frontage of a legion in its standard deployment. This means the Romans have calculated how many cavalry squadrons can fit within the frontage of a legion. For example, at Cannae Paullus would know that the frontage of his army both infantry and cavalry was equivalent to 36 legions. By doubling his depth, the frontage would be equivalent to 18 legions. It’s actually a square measuring system and is simple and very effective. So theoretically a commander can assign those units in a square different deployment arrangements, or even have one unit cover two squares if need be. This system can tell what the standard frontage and depth of a cavalry squadron should be. I’ve applied the Roman deployment system to the 8000 auxiliary infantry at Mons Graupius and it strongly points towards them belonging to cohors equitata miliariae. This means a large part of the 3000 cavalry also belong to those auxiliary cohors equitata miliariae.
The deployment arrangement I have ended up with has two lines, the second line consists of two legions each flanked by two alae and the remainder of the cavalry are deployed on the flanks of the auxiliary infantry. I believe the cavalry deployed on the flanks of the auxiliary infantry are the ones mentioned frontally attacking the Caledonians. Even with the auxiliary infantry extended, the auxiliary line has a shorter frontage than the second line. As the staff officers wanted to deploy the legions with the auxiliary infantry this indicates the depth must be the same as the auxiliary infantry and this rules out the legions being core legions (not full legions). From this I believe Agricola wanted his first line to be shorter in order to tempt the Caledonian reserve sections to come down the hill and attack the first line in the flank.
If I reverse this deployment and have only four squadrons in reserve it just looks wrong as the strike power is extremely whimsical, plus the Romans have too much cavalry in the first line. However, if it can be proven to me that “quatuor equitum” does categorically mean squadron then its back to the drawing board for me.
