Geoffrey, Nennius and the Invasion of Britain

Geoffrey of Monmouth's Historia Regum Britanniae is a cause of significant debate amongst Arthurian theorists. The author claimed to have been translating one particular 'ancient book written in the British tongue'. However, this claim has been seriously contested, and it is now felt by the majority of scholars that Geoffrey simply created his own account from the various different sources he had at his disposal, such as the works of Gildas, Bede, the Welsh Annals, the Historia Brittonum, and the genealogies such as those found in the Harleian MS 3859. On the other hand, there are those who insist that Geoffrey was telling the truth and that there did exist one particular source, now lost to us, which Geoffrey translated.

The first school of thought generally encapsulates the idea that Geoffrey did not possess any sources that we do not now have, which would mean that his Historia Regum Britanniae can offer no unique historical insights. In contrast, the second school of thought absolutely allows for the possibility that HRB contains some valid historical traditions not found anywhere else.

I am not going to settle this whole debate in one blog post, but what I will do here is address one particular claim regarding Geoffrey's sources. It is claimed that he clearly got his account of Julius Caesar's invasions of Britain in 55 B.C.E. and 54 B.C.E. from the account found in Historia Brittonum, commonly attributed to Nennius (such attribution is no longer widely accepted, but it will be used here, as it is throughout my blog, for the sake of simplicity). Is this a sensible conclusion? Is this a conclusion that really follows what the evidence shows, or it is a conclusion that has been reached simply because there is no other way of explaining Geoffrey's account without accepting that he had access to sources no longer available to us?

The account found in Historia Brittonum is very brief, so it will be quoted in full here:

Then Julius Caesar, the first who had acquired absolute power at Rome, highly incensed against the Britons, sailed with sixty vessels to the mouth of the Thames, where they suffered shipwreck whilst he fought against Dolobellus, (the proconsul of the British king, who was called Belinus, and who was the son of Minocannus who governed all the islands of the Tyrrhene Sea), and thus Julius Caesar returned home without victory, having had his soldiers slain, and his ships shattered. 

But after three years he again appeared with a large army, and three hundred ships, at the mouth of the Thames, where he renewed hostilities. In this attempt many of his soldiers and horses were killed; for the same consul had placed iron pikes in the shallow part of the river, and this having been effected with so much skill and secrecy as to escape the notice of the Roman soldiers, did them considerable injury; thus Caesar was once more compelled to return without peace or victory. The Romans were, therefore, a third time sent against the Britons; and under the command of Julius, defeated them near a place called Trinovantum [London], forty- seven years before the birth of Christ, and five thousand two hundred and twelve years from the creation.

It is easy enough to compare this account with the account provided by Geoffrey of Monmouth in Historia Regum Britanniae. The reader can then see for himself whether or not it is logical to conclude that this was the origin of Geoffrey's version of events.

First, let us consider the invasion of 55 B.C.E.:

"Julius Caesar, the first who had acquired absolute power at Rome, highly incensed against the Britons, sailed with sixty vessels to the mouth of the Thames,"

Geoffrey includes plenty of numerical information in his book, but he does not include this.

"where they suffered shipwreck"

Geoffrey makes no mention of this.

"whilst he fought against Dolobellus,"

There is no Dolobellus in Geoffrey's account. The closest thing is Dorobellum, where Cassivellaunus holds council before attacking Caesar's army.

"(the proconsul of the British king, who was called Belinus,"

Belinus does appear, but he is only the general of the army, while the king is Cassivellaunus.

"and who was the son of Minocannus who governed all the islands of the Tyrrhene Sea),"

This certainly doesn't appear!

"and thus Julius Caesar returned home without victory, having had his soldiers slain, and his ships shattered."

Again, there no mention of any damage being received by his ships in Geoffrey's account.

Thus, in almost every single statement made by HB, it differs from HRB. Yes, they have general similarities, but that is simply because they are talking about the same historical event. Of course they have similarities. But in virtually all the details, the two accounts are completely dissimilar.

Now, let us look at the second invasion:

"But after three years he again appeared with a large army,"

According to Geoffrey of Monmouth, it was two years, not three.

"and three hundred ships,"

Again, Geoffrey does not include this numerical information, despite clearly being perfectly willing to put numerical information in his book.

"at the mouth of the Thames, where he renewed hostilities. In this attempt many of his soldiers and horses were killed; for the same consul had placed iron pikes in the shallow part of the river,"

'the same consul' is Dolobellus, yet he is not mentioned here in HRB, just as he was not mentioned earlier. The HRB attributes the stakes to Cassivellaunus.

"and this having been effected with so much skill and secrecy as to escape the notice of the Roman soldiers, did them considerable injury; thus Caesar was once more compelled to return without peace or victory. The Romans were, therefore, a third time sent against the Britons;"

This is the only example of an inaccuracy in the HB which is also present in the HRB, and is thus the only possible reason for concluding that they are in any way textually related. But this could very easily be attributed to a common source.

"and under the command of Julius, defeated them near a place called Trinovantum,"

Trinovantum is featured numerous times in HRB, but it is not mentioned here. Instead, Geoffrey gives Dorobernia (Canterbury) as the location of Cassivellaunus's defeat.

Once again, the reason they are similar is because they are describing the same event. The only detail that could possibly lead anyone to conclude that one was dependent on the other is the information about the 'third' invasion, as I mentioned earlier. But that is easily explained as deriving from a common source. The idea that HB was the actual source used by the writer of HRB for this event completely flies in the face of the facts concerning what HB says and what HRB says.

Of course, this conclusion presents a problem for those who subscribe to the idea that Geoffrey did not possess any historical sources that we don't now have. If Geoffrey did not use HB, then where did he get this information from? HRB is evidently textually related to HB to some degree (as is apparent by the claim of three invasions instead of two, and the inclusion of the apparently fictional 'Trinovantum'), but as has been clearly shown here, the account cannot have been taken directly from HB. So this would result in the conclusion that there was indeed a separate British account of this invasion which Geoffrey had access to.

Interestingly, as a final comment, it should be noted that when Geoffrey's account is stripped down to the same level of brevity as Nennius's, it is by far the more accurate version. Yet Geoffrey's account is supposed to be a later development from Nennius's. So, if we go along with the current consensus, we arrive at the incredible and frankly ridiculous conclusion that Geoffrey of Monmouth took Nennius's account, embellished it, and accidentally made it more accurate.