55 BC: Invasions of Germany & Britain
During the following winter, Caesar was forced to deal with an invasion into Gaul of two German tribes, the Usipetes and the Tencteri, who had been forced to migrate because of attacks on them by the Suebi. The Suebi were the largest and most warlike of the Germans; their men alternated between military service for a year and the cultivation of grain, following a strict diet and lifestyle and not allowing any other tribesmen to live on their borders, hence the reason why they drove away these tribes.
When the Usipetes and Tencteri reached the Rhine, the Menapii abandoned their villages on that side and prevented them crossing but were duped into thinking they had withdrawn and, when they returned to their villages, the invaders killed them, seized their boats and crossed into Gaul, where they spent the remainder of the winter. When Caesar heard about this, he rejoined his army earlier in the season than usual as he had suspicions that the Gauls were easily swayed and made decisions on the spur of the moment and he did not want to be faced with a dangerous war; and these suspicions were confirmed as some Gallic tribes had encouraged the Germans to travel further afield into other areas.
Having ordered local leaders to provide cavalry for his campaign, he marched towards the Germans. They sent an embassy to Caesar, asking for peace and saying they had no quarrel with the Romans, who should either give them land on which to settle or allow them to keep what they had taken. Caesar told them they must leave Gaul; they could not take land belonging to others; he offered them land in the territory of the Ubii who had also been attacked by the Suebi. Using delaying tactics to allow their cavalry to return from a foray, the Germans requested three days to consider the offer and a further three days to negotiate with the Ubii. They then attacked five thousand Roman cavalry which Caesar had sent ahead and put them to flight, killing seventy four including Piso, a good friend to Rome from the Aquitani tribe, and his brother. Angered by this treachery, Caesar, after detaining the leaders of the Germans who came to apologise for the attack and to ask for another extension of the truce, quickly marched against the Germans and caught them off guard. Resistance was short and the majority fled towards the Rhine, hotly pursued by the cavalry. Large numbers were killed by the Romans or drowned in the river while the Romans suffered no fatalities and very few wounded. Those Germans who had been detained were given permission to leave but chose to stay, fearing recriminations from the Gauls.
Caesar then decided to cross the Rhine with the following three objectives: firstly to alarm the Germans so they would be less inclined to cross into Gaul, secondly because the cavalry of the Usipetes and Tencteri, who had not fought in the battle, had joined forces with the Sugambri, who would not hand them over and they needed to be punished, and thirdly to morally support the Ubii against the Suebi.
He decided to build a bridge across the Rhine by lowering pairs of piles into it and joining them by wooden beams, work which took ten days. Having placed guards at either end, Caesar marched into Sugambri territory, burning their villages and crops when they fled. Then, having been told by the Ubii that the Suebi had abandoned their towns and hidden their women, children and possessions, and were ready to fight the Romans, Caesar did not attack but withdrew into Gaul and destroyed the bridge as he had achieved his three objectives.
Near the end of summer, Caesar decided to launch a fact-finding expedition to Britain from the northern coast of Gaul as he knew the Gauls received reinforcements from there but he knew nothing about the island’s geography or tribes. He sent a warship with C. Volusenus in command, whilst marching his army into Morini territory from whose coastline was the shortest crossing to Britain and he gathered a fleet there. The Morini, previously hostile, apologised for their past behaviour and pledged their loyalty, handing over hostages as a sign of goodwill. Once the Britons learned of Caesar’s intentions from traders, they sent envoys offering to submit to Rome and hand over hostages, which Caesar accepted, and sent them home accompanied by Commius, king of the Atrebates, whom he trusted and the Britons respected, with instructions to visit as many British tribes as possible and urge them to put themselves under Rome’s protection.
Volusenus returned four days later having completed his mission without disembarking. Having assembled eighty transport vessels to convey two legions, eighteen farther along the coast to transport the cavalry and with a number of warships, leaving P. Sulpicius Rufus in charge on the Gallic coast, and having ordered Q. Titurius Sabinus and L. Aurunculeius Cotta to march against those Morini who had not sent envoys, he set sail at midnight with favourable weather and arrived in Britain nine hours later.
Waiting for six hours until all his forces had arrived, he landed mid-afternoon but they were attacked by Britons, who had the advantage over the soldiers trying to disembark as well as ward them off. Caesar moved the warships close to shore, whose men initially hurled missiles from their decks and then followed ashore the aquilifer of the tenth legion. In the ensuing hard fought battle, the Britons had the advantage until Roman troops in boats were deployed where they were needed and the battle began to turn in the Romans’ favour but ultimate success eluded Caesar because of the absence of the cavalry, who had failed to arrive because of adverse tides.
However, the Britons sued for peace, sending as their spokesman, Commius, whom they had initially taken prisoner but now freed. Hostages were demanded and given. Four days later, the eighteen transports conveying the cavalry approached but were prevented from landing by a great storm, which also damaged irreparably a number of other ships and prevented the Romans’ return to Gaul. Seeing the Romans’ plight, the Britons therefore stopped sending hostages and decided to renew hostilities to prevent the Romans obtaining supplies and hoping to overcome or prevent them returning to Gaul.
Caesar, meanwhile, had managed to repair and make seaworthy all but twelve ships but, as the seventh legion was gathering corn from nearby fields, the Britons attacked them in chariots and with cavalry. They were saved by the approach of Caesar and the Britons retreated but gathered more forces over the next few days of bad weather when neither side attacked. When fighting resumed the Romans gained the upper hand and, using cavalry brought across by Commius, pursued the Britons as they fled, killing some and setting fire to buildings over a wide area. British envoys again sued for peace which was accepted with twice as many hostages demanded which were to be brought to Gaul. Only two British tribes sent them.
Caesar and his troops set sail at midnight for Gaul and all arrived safely, although two transports landed farther south than the rest. The three hundred soldiers on board were attacked by the Morini, quickly joined by six thousand other tribesmen. The Romans defended themselves for over four hours until they were rescued by cavalry sent by Caesar, at whose arrival the Morini fled, having suffered heavy casualties. Labienus and the legions who had returned from Britain captured them while Sabinus and Cotta burned all their crops and homes. Caesar wintered his troops in Belgic territory. The senate decreed a public thanksgiving of twenty days when they received news of his victories.