The approximate number of boats  in the fleet that carried the invading Roman army to Britain in 54 BCE. Of these, 28 were dedicated warships and most of the rest were troop transports. They used for troop transports both Standard warships and merchant ships, likely more merchants (when it’s not mentioned) than warships, which would’ve been less effective and more unusual. But there are definitely plenty of examples of both.
In place of the boats Caesar now had a bridge constructed. By a remarkable effort it was completed in ten days. Caesar gives a long, technical description of its building which has generated prolonged controversy over its detailed construction. Its location is equally uncertain but most probably across the middle Rhine between Andernach and Neuwied just north of Coblenz. The bridge was an impressive feat of engineering. In this area the Rhine is on average 1,300 feet wide and about 20 feet deep.
In 58 BC two German tribes, the Usipetes and Tencteri, under attack by the Suebi and unable to withstand the pressure, began a westward migration. Probably in January 55, after three years of wandering, they crossed the lower Rhine and entered the territory of the Menapii who had settlements on both sides of the river. At the arrival of the Germans they evacuated their settlements on the eastern bank and garrisoned the right bank to guard against a German crossing. Lacking boats the Germans entered into negotiations with the Menapii but these ended in failure. Pretending to retreat from the river the Germans deceived the Menapii, who relaxed their guard. A night attack by German cavalry killed the guards on the right bank and the Germans seized the Gauls’ boats. Once across they gained control of part of the lands of the Menapii, using their provisions and occupying their dwellings.
Caesar was in Cisalpine Gaul when he learned of the German crossing. He set out for Transalpina earlier than usual to prevent a more serious situation from developing. After he joined his army he learned that the arrival of the Germans had had further repercussions. As the Sequani had done earlier, several of the Gallic tribes invited the Germans to serve as mercenaries in intertribal wars. Encouraged by these invitations the Germans had moved into the territory of the Eburones and Condrusi who lived in the area between the Meuse (German Maas) and the Rhine and were Roman clients.
In response Caesar called a meeting of Gallic leaders. Here he probably means those of the central Gallic tribes, to rally support and to remind them of where their loyalties lay. He also levied cavalry from them both for military reasons and as hostages to assure good behaviour. After making arrangements to secure his grain supply he set out in the direction of Coblenz to confront the Germans. When he was only a few days march from them they sent envoys to him and requested lands to settle in – either those they already held or some other area designated by the Romans – and in addition offered themselves as allies. Caesar refused their request for their settlement as it would have upset his relations with the Gauls and the stability he had achieved, but offered them land on the other side of the Rhine in the territory of the German Ubii, which lay between the River Lahn and the Taunus Mountains.
The envoys asked for three days to consider Caesar’s offer. They requested that during the three days Caesar would not move his camp closer to their position. Caesar refused. He claims that the reason for this refusal was the fact that he had received intelligence that they had sent a large force of cavalry across the Meuse to loot and forage in the lands of the Ambivareti and that the delay was merely an excuse to put off fighting until the return of this force.
Caesar now advanced against them and when he was about eleven miles from their camp their envoys reappeared once again asking him to proceed no farther. Failing in this request they asked that he order his cavalry not engage them and to allow them to send an embassy to the Ubii. They said that if the Ubii accepted they would agree to Caesar’s terms. They asked for another three days to accomplish this. Caesar claims that in spite of his misgivings he agreed to go no farther than another four miles in search of water, and he ordered the Germans to assemble where he halted in full force and he would make a decision about their request. He then sent a message to his cavalry commander not to launch an assault and if he was attacked to wait until Caesar came up with the infantry.
The majority of the German cavalry was still absent when the 5,000 Roman auxiliary cavalry came into view. Despite the odds the 800 German horsemen charged and threw the auxiliary cavalry into disorder. When the Roman cavalry turned to resist, the Germans dismounted as was their custom, stabbing the horses and pulling their riders off until they finally routed the Romans, killing seventy-four of them. The rest turned in headlong flight until they came up with Caesar’s column. The disparity in numbers makes this rout surprising and it does seem suspicious. Caesar had already mentioned the fact that certain unnamed Gallic tribes had offered invitations to the Germans and they may have deliberately fled so as not to alienate the Germans. On the other hand there was a later occasion when a small force of German cavalry in Caesar’s service defeated a much larger body of Gallic cavalry.
The cavalry battle now persuaded Caesar that instant action was unavoidable. The rout of the cavalry would be seen as a defeat and persuade the Gauls who were unhappy with the Roman presence that Caesar’s forces were vulnerable. The next day a delegation of leading Germans appeared to apologize for the action, which may well have been unplanned. Caesar, who this time was not worried about violating the sanctity of envoys, detained them. He now marched against the leaderless Germans with his entire force, placing the cavalry at the rear as he was uncertain of their morale and loyalty. He deployed his army in a classic triple column of march so as to be ready for a sudden attack. Marching at the double he quickly completed the seven miles to the German camp and surprised them. The sudden appearance of Caesar and his army threw the unprepared Germans into confusion. The Romans broke into the camp. Those Germans who had arms resisted for a little while, fighting among their baggage and wagons; but the others, including the women and children, fled. Caesar sent his cavalry in pursuit. During the flight German morale broke down completely. They abandoned their weapons and standards rushed out of camp in an attempt to cross the river to safety. Caesar says that they fled to the confluence of the Meuse and Rhine: that is, to the Rhine-Meuse Delta in the Netherlands. But depending on the geography of the campaign, some place the battle near the confluence of the Moselle and the Rhine near Coblenz. The first alternative is preferable. It is supported by the text and by a not entirely accurate description of the course of the Meuse earlier in the text. The flight was a disaster; when the Germans reached the Rhine a great number had been killed and many more drowned in the river.
Caesar claims that he had few casualties and none of them fatal. He gives the number of the combined tribes as 430,000 and a later source, his biographer Plutarch, claims that 400,000 of them perished. These figures give one pause, especially Plutarch’s figure for those killed. This seems an impossibly large number given that the pursuit and the slaughter extended over a significant distance and that some of the dead drowned in the Rhine. No figure can be regarded as even remotely accurate. It is difficult to believe that both tribes were as devastated as Caesar implies. Certainly they were still capable of causing further trouble for the Romans in the last decades of the century.
Caesar’s enemies fiercely criticized his conduct in this campaign for the bad faith he had shown with the German emissaries. A commission of inquiry was voted by the Senate but it is doubtful that it was ever sent. Caesar had the year before made one of his reasons for going to war against the Veneti the detention of Roman officials who were in fact not envoys. Although he does make an attempt to exonerate himself by suggesting the cavalry attack was purposeful, he does not hide the basic facts of the situation. His political enemies may have seen this incident as a weapon to use against him, but it is doubtful, given the Roman attitude towards the northern barbarians, that this act was politically damaging.
Caesar now decided to cross the Rhine. He thought a demonstration on the right bank of the river might act as a deterrent to further German attempts to cross into Gaul. In addition, if he crossed the river he would be the first Roman general to do so and this might further mute any criticism of his actions against the Germans and add to his prestige. He also wanted to pursue the German cavalry, which had been absent at the time of his victory over the Usipetes and Tencteri. They had crossed the Meuse in search of food and plunder and then retreated back over the Rhine to the territory of the Sugambri, whose lands lay between the Lahn and Ruhr rivers, and made an alliance with them. Learning of this Caesar sent messengers to the Sugambri to demand the return of the fugitives. They refused his request, claiming that Roman power ended at the left bank of the Rhine and that what they did was no business of Caesar’s. His victory had not impressed many of the German tribes: only the Ubii sent a delegation and concluded a treaty of friendship with Rome. They had good reasons to do so. They, like the Usipetes and Tencteri, were under pressure from the Suebi, and Caesar provided a possible solution to that problem. They offered boats to ferry his army across the Rhine. Caesar rejected this offer. He was worried about the safety of the crossing. The Ubii may have appeared anxious for his help but how could he be sure of them? He adds that such a crossing would not be consistent with his own or the Roman people’s dignity. Certainly, dignity was an important Roman political and social concept signifying the respect that other individuals or communities accorded a person or a group. It is hard to understand what it means in this context. Perhaps of more importance was the use of Roman engineering skills to impress the Germans. In place of the boats Caesar now had a bridge constructed. By a remarkable effort it was completed in ten days. Caesar gives a long, technical description of its building which has generated prolonged controversy over its detailed construction. Its location is equally uncertain but most probably across the middle Rhine between Andernach and Neuwied just north of Coblenz. The bridge was an impressive feat of engineering. In this area the Rhine is on average 1,300 feet wide and about 20 feet deep.
During the construction Caesar was approached by a number of German tribes seeking peace and alliance. He received their requests favourably, asking that they turn over hostages as a pledge of good faith. It is not clear that these hostages were ever handed over, but later on Caesar was able to recruit German mercenaries so his action must have had some effect. Leaving a guard at the bridge the Romans marched into the territory of the Sugambri, who had already fled once they learned of the construction of the bridge. As some of the Gauls had done, they sought refuge in the forests taking all of their property with them. Caesar remained for a few days in the territory of the Sugambri laying it waste and then moved on to the lands of the Ubii. There he made an explicit promise to the tribe that he would aid them against the Suebi. Meanwhile he learned from Ubian scouts that the Suebi had assembled all of their men capable of bearing arms in the middle of their territory and would fight a decisive battle there with the Romans. The spot was too remote for an expedition and so Caesar recrossed the Rhine, destroying the bridge behind him.
Although Caesar claims that he had achieved his goals of overawing the Germans, punishing the Sugambri and of aiding the Ubii, it is hard to see the German expedition as a success. The few days spent in destroying the property of the Sugambri and the uncertain German promises of peace and friendship counted for little. The Sugambri had evaded him during his eighteen-day stay across the Rhine. He did not confront the Suebi, who were the main Roman problem in western Germany, and it is difficult to know how serious his promise of support to the Ubii was. Also Caesar exaggerates the importance of the Rhine as a dividing line between Gaul and the Germans. The German tribes of the Eburones and Atuatuci were already settled to the east of the Nervii. It was not this campaign east of the Rhine that was significant but Caesar’s string of victories in Gaul that made the difference. It is likely that had Caesar not campaigned, the Germans would have increased their migration into Gaul and occupied much of it.
Despite the fact that it was late in the campaigning season, probably in late July, Caesar made preparations for his expedition to Britain. At this point in his narrative he claims that the reason for the expedition was that the Gauls had received help from their kinsmen across the Channel. The biographer Suetonius mentions another reason: Caesar’s lust for pearls. This is hardly persuasive. Although Caesar mentions other natural resources he is silent about the pearls, and some later Roman writers considered British pearls to be small, discoloured and dark. Writing within a generation of Caesar’s death the geographer Strabo mentions that the island produced slaves, hides, gold, silver and tin but in Caesar’s generation far less was known about the products of British mining. Cicero mentions that he had heard that there was no gold or silver in Britain. Caesar indicates that there was tin and iron but says nothing of precious metals. There was a substantial trade with the tribes on the northwestern coast as far south as the Loire. But this was not a Roman concern. Caesar claims that the merchants who traded with the Britons knew only the part of Britain facing Gaul and were of little help. It may well be that they were afraid of the effects of an invasion on their established routes and customers, but that does not indicate that they feared they would be replaced by Romans and Italians. An invasion would upset their established relationships and make movement unsafe. These were reasons enough to be reluctant to provide the Romans with information. There is no doubt that the desire for wealth played a role in Caesar’s decision, but it was made for booty, not trade opportunities.
Caesar’s claim that the Britons provided support to the Gallic tribes in their struggle with the Romans may be true but exaggerated. He records that south-eastern Britain was inhabited by Belgae, who had invaded the area and then settled it. Coinage and other archaeological evidence point to successive migrations by Belgae beginning about a century before Caesar’s arrival on the island. There were certainly ties between the Belgic tribes in Britain and those on the continent. In his discussion of the continental Belgae Caesar mentions that within living memory Diviciacus the king of the Suessiones had also ruled Britain, presumably in the Belgic south-east. In 57, after the defeat of the Belgae, chiefs of the Bellovaci who had persuaded their people to fight fled to Britain. In 55 on the eve of his first landing in Britain Caesar sent out Commius, whom he had made king of the Atrebates, to Britain as an envoy because he possessed great influence there, presumably among the Atrebates settled in Britain. Despite these ties Caesar provides no evidence of substantial British support for his enemies in Gaul.
The most important reason for the invasion is to be found in Caesar’s political position at Rome. If he had originally planned the invasion for 56 his attempt to link it to the security of Gaul, which he now claimed was pacified, would provide a further reason to extend his command. His prestige would be bolstered by being the first Roman to bring an army across the channel. The British invasion has its counterpart in his crossing of the Rhine. Both were ways of justifying Caesar’s command and enhancing his standing. These actions seem aimed less at Germans and Britons and more at his political enemies in Rome. The quest for wealth was certainly a motive but a subordinate one.
The first landing in Britain in 55 was little more than a reconnaissance in force. Caesar brought his legions to the Pas de Calais in the territory of the Morini who, now overawed by the concentration of force, surrendered. The army he assembled for this campaign was certainly too small to accomplish more than to prepare the way for a larger expedition. It consisted of the Seventh Legion and his favourite, the Tenth, lightly equipped to save space, and a force of cavalry sailing in a separate convoy from a different port. He must have expected that he would be met by British tribes with whom he had already been in diplomatic contact before he sailed and that they would make a formal submission. Caesar does not mention the port from which he sailed in 55 but in the next year he sailed from Portus Itius, whose location is uncertain but may be Boulogne, and it may well have been the port he used the year before.
When Caesar left the cavalry had not yet embarked and a change in the weather prevented it from joining him. When he had sailed on 26 August Caesar had chosen the natural harbour at Dover for his landing, but the steep cliffs covered with defenders made a landing there impossible. He sailed north along the coast, probably landing between Walmer and Deal. The British had kept pace with his ships as they sailed from Dover and were ready to oppose his landing. Despite having to disembark in the water because of the sloping beach the troops forced their way onshore and routed the British, but pursuit was impossible without the cavalry. In this initial encounter the Romans had their first experience of chariot fighting. The chariot was still used by the British Celts long after it had been abandoned in Gaul and Caesar was impressed enough to add a digression on it to Gallic War.
A storm four days later severely damaged Caesar’s ships. This led to renewed fighting with the British, who were once again defeated. These successes had some effect. A number of tribes submitted and as a penalty for their initial refusal to surrender Caesar doubled the number of hostages he demanded and ordered the tribes to transport them to Gaul. Given the lateness of the season – it was close to the autumnal equinox – Caesar returned to Gaul. The expedition had almost ended in disaster because of the weather. The force was too small to achieve anything significant, insufficient attention had been paid to the weather in the Channel, and too little time had been spent in preparing for the crossing. Despite its shortcomings the British expedition produced the political results that were all that Caesar could have wished for: he was voted a twenty-day thanksgiving by the Senate.