The only ancient source that recounts the invasion of Britain in 43 in full is Dio. Added details, however, may be gleaned from Suetonius (whose main entry concerning the invasion is fairly dismissive), and, also, from Tacitus, Josephus and Eutropius.
According to Dio, Claudius had reputedly ordered the invasion because ‘Berikos’, had fled Britain as the result of an uprising. We can identify Berikos from Celtic coins as Verica, a king apparently of the Atrebates and thus perhaps a descendant of Commios, the Gaulish Atrebate and erstwhile ally of Caesar in 54 BC. Of course the invasion was a pretext for war. Rome, after all, had nothing to fear from Britain.
At the same time as these events were happening in the City Aulus Plautius, a senator of great distinction, led a campaign to Britain, since a certain Berikos [Verica], who had been driven out of the island as a result of an uprising, had persuaded Claudius to send a force there.
Cassius Dio Cocceianus, The Histories of Rome, Book 60, Chapter 19
Claudius gathered together and formidable army. Studying and learning from the failures of Julius Caesar, Claudius planned this invasion with the utmost care — his first action was to retire those soldiers who did not reach a set level of fitness.
Planning the invasion
This time, a great deal of planning by Claudius went into this invasion attempt. Four years previously, the Emperor Gaius (most commonly known by us, as “Caligula”) had planned such a mission, but it had ben abandoned. The main reason for the reluctance to launch an invasion, was due to an element the Romans had not encountered many times before, yet had nearly defeated them both times. The sea, between Gaul and Britain, had been the downfall of Caesar twice.
The Roman troops were superstitious and quite terrified of the channel crossing, as they knew of the dangers this stretch of water could bring. It may seem strange to us, according to the writings of Suetonius, the Roman hierarchy took it seriously as, to aid the boats in their travels, a lighthouse was built at Boulonge by Caligula, to act a beacon for the craft passing across the channel.
As a monument of his success, he a lofty tower, upon which, as at Pharos, he ordered lights to be burnt in the night-time, for the direction of ships at sea[.]
Suetonius: The Twelve Caesars: The Life of Caligula Book Three, Chapter 46
A Delayed Boarding – Weather and Galba?
Aulus Plautius was forced to delay the landing until late in the year because of the unpredictable weather conditions. Suetonius, noted that the delay was claimed to have been caused by a minor illness to (the future emperor) Galba a friend to Emperor Claudius.
[Galba] was in great favour with Claudius, and being received into the number of his friends, stood so high in his good opinion, that the expedition to Britain was for some time suspended, because he was suddenly seized with a slight indisposition.
Suetonius: The Twelve Caesars: The Life of Galba Book 7, Chapter 7
A Delayed Boarding – Mutinous Troops
For reasons unclear, the supreme commander, Plautius, was unable to exert his authority, so he turned to Rome for help. This came in the form of Narcissus, a Freedman who used his position as correspondence secretary (ab epistulis) to the Roman emperor Claudius to become, in effect, a minister of state — the Secretary for State, and a close advisor to Claudius. Narcissus managed to persuade the troops into boarding. Because of his background, he was more on the same level with the troops and managed to get them to board the ships, even with their superstitions.
So it was that Plautius undertook the expedition, though he had difficulty in getting his army to leave Gaul, since the troops were indignant at the prospect of campaigning outside the known world, and would not obey him until Narcissus, who had been sent by Claudius, mounted Plautius’ tribunal and tried to harangue them. Thereupon they became even more angry and refused to allow him to speak at all, but suddenly all in unison they raised the cry ‘Io Saturnalia’ – at the festival of Saturn the slaves take over the role of their masters and engage in festivities – and at once they willingly followed Plautius.
Cassius Dio Cocceianus, The Histories of Rome, Book 60, Chapter 19
Crossing of the Channel
Cassius Dio recorded the happenings of the invasion. He stated that there were three divisions, not one.
They made the crossing in three divisions so as not to be hampered in landing, as a single force might be.
Cassius Dio Cocceianus, The Histories of Rome, Book 60, Chapter 19
This would mean three separate landings, making the defence of Britain harder than if just one beach was chosen. It is unclear whether this meant three separate landing spots, or or a staggered arrival in one place. Three groups may have been used so that the first group would secure a landing, then the other would follow and land. It is stated that three legions were involved at the Medway battle, so it’s likely that there was one landing point, with the fourth legion being held in reserve.
Unopposed Landings
The landing at Richborough (Rutupiae) was unopposed and the Britons at first seemed reluctant to battle the Romans. The Britons, misled by the news of the mutiny had already dispersed.
On putting in to the island they met with no resistance, since the Britons, from what they had learned, had not expected them to come, and had not assembled beforehand. Even when they did assemble they did not engage the Romans, but took refuge in the marshes and woods hoping to wear them out by these tactics, so that they would sail back empty-handed, as had happened in Julius Caesar’s day.
Cassius Dio Cocceianus, The Histories of Rome, Book 60, Chapter 19
Caratacus and Togodumnus fight a delaying action
When news of the landings reached Caratacus, all he had available were his own followers and warriors and it would have taken some time for him to assemble a force big enough to fight the Roman legions. He set a rally point for his allies on the far side of the River Medway. Caratacus and Togodumnus needed to delay the Romans as much as possible to allow time for their allies to muster and so began a skirmish delaying action.
Plautius, therefore, had a good deal of trouble in searching them out, and when he did eventually locate them, he defeated first Caratacus and then Togodumnus, the sons of Cunobelinus, who was now dead.
Cassius Dio Cocceianus, The Histories of Rome, Book 60, Chapter 19
The Surrender of the Dobunni
Plautius secured the surrender on terms of part of the Bodunni [Dobunni] tribe who were subject to the Catuvellauni. Leaving a garrison there he advanced further and came to a river.
Cassius Dio Cocceianus, The Histories of Rome, Chapter 20
The tribe mentioned by Cassius Dio is thought to be the Dobunni Celtic Tribe, a significant tribal group situated in Gloucestershire. He possible made an error error in transposing the letters b and d. Bodunni with Dobunni is the fact that no other ancient author mentions the former, where as the latter is known. Although it does beg the question why a tribe from Gloucestershire, albeit, subject to the Catuvellauni should be in Kent.
The Dobunni had two rulers which implies two sections of this tribe, also that it seems possible that the northern half had an alliance with Cunobeline who was an ally of Rome. This would have meant that the tribe already had contact with Rome. The imported pottery found at their capital, Bagendon, which dates to AD 15–358 probably came via one of the south-coast points of entry. This section of the Dobunni, already in contact with Roman trade correctly supposed that the wily Cunobeline. While honour bound to provide levies to Caratacus and meet him on the Medway, they probably planned to seek out the Roman commander and sue for peace if the availability presented itself. Plautius regarded this as useful as his policy of war was to divide and conquer.
Cassius Dio mentions leaving a garrison there, which presumably means the place where they met the Dobunni. The location of the fort for this garrison is unknown but its rough position may be deduced. The British probably first attacked the Romans at the crossing of the Stour, where wooded terrain would have been much more to their advantage than the open downs to the west. With this in mind a fort may be found at Canterbury (Durovernum) where there is now evidence of a military timber building and of a large Gallo-Belgic oppidum which would have been useful in the event of a retreat. The only other known military sites in Kent are at Richborough (Rutupiae) and Reculver (Regulbium) Fort.
Continue reading in The Battle of Medway (43 AD).