Britain invaded! (2)

In my previous post, I discussed the difficulties of describing the Roman invasion of Britain in my novel Legatus Legionis regarding the sailing, and where the invasion forces landed. The next problem involved what happened next? According to Cassius Dio, the first major battle involved two legions, and was fought near the mouth of a river that the Celts seemed to think would be an obstacle for the Romans. This river is usually considered to be the Medway, although as far as I am aware, there is no physical evidence for this, other than a shortage of alternative rivers. Dio appears to say that the Celts stayed by and large behind fixed defensive walls, but also says there was a battle that lasted two days, which was somewhat unusual for the times. The Romans started proceeding when some Batavians swam the river and scattered the Celtic horses, while some Romans led by Hosidius Geta crossed, and found themselves in deep trouble with the Celts, so much so that Geta had to personally join the line. Dio implies that Geta was a legatus, but I find that very difficult to believe. If a commander joins the line, it means that either the Roman squad was hopelessly outnumbered, and that should not happen if a legion crossed, unless the battle was going very badly. There are no records of a legion nearly being wiped out, so it had to be a smaller squad. But no commander of a legion is going to abandon his legion and go off on an adventure with a small squad, so I assumed that Geta was a Tribune, at least at the time.

The next problem was that Dio is fairly emphatic that two legions were involved in this battle, and one of them was the Augusta under Vespasian. But Vespasian’s main objective was to secure the alliance on the south coast. The nominal reason for the invasion was to support Cogidumnus as a client king. The whole point of the invasion was to govern it after the military force succeeded, and it was general Roman policy to have locals governing, at least in name. Roman power would have the last word, but it was a lot easier if someone would do what they wanted for them. To me, the guiding principle is that Cogidumnus was allying himself with Rome because Caratacus had effectively declared war on him. If Rome did not support such an ally, why would any other Celtic tribe support Rome? In the absence of evidence to the contrary, I believe Vespasian and the Augusta would ensure Cogidumnus and his domain were safe, and in doing that he may well have had to fight a battle. There is real archaeological evidence for a battle well to the south of the Medway, although the dating is not absolute, and it could have been prior to the Roman invasion. My interpretation was that this southern one was due to Caratacus trying to deal with the southern Celts who had allied themselves to the Romans, and Vespasian had to deal with them. What the other two legions fought was the remains of this badly mauled Celtic force plus reinforcements after they retreated north and set up camp. That has the advantage of being in accord with the proposition that Vespasian had a major battle in these early stages, and all legions were involved. I cannot believe that in a major invasion, one third of the force would be absent and doing nothing.

This brings up the major difference between writing a historical novel and writing a history. In a history you can consider all the options. In a novel, things happen, and there is no “half-happening” and no “either or”. Further, everything has to be self-consistent. Then, after having gone to all this trouble, there remains the interesting story to write, because all that has been set so far is the background.