Julius Caesar Invasion Of Britain 55 BC

The Battle of Cropredy Bridge, fought on 29 June 1644, was complex in its fighting, yet simple in its origin. If ever a battle was fought simply because there were two opposing armies close to one another and able and willing to fight, this was it.

Their commander had assumed that the two legions he had brought with him, just over 10,000 men, would have come ashore on dry land at Dover hours beforehand without a shot being loosed. Instead, the 100-strong Roman fleet had been driven several miles along the coast to an unfamiliar beach near Deal.

Here, his men, weighed down by armour and heavy equipment, were forced to jump several metres from the side of their transports into shoulder-deep seawater. As they waded towards terra firma through unknown shallows, hardly able to push through the waves let alone keep rank or fight, they were set upon by British warriors from the shore.

The British attacked ferociously, driving chariots into the sea, hurling spears, shouting curses, and cutting down many Roman soldiers in the chaos.

Glory versus generalship

Julius Caesar This fiasco had nothing to do with bad luck over the weather or the prowess of British warriors. The fault lay with Caesar. He had allowed his drive for glory to get the better of his generalship.

Caesar claims in his own account of the war – De Bello Gallico, ‘The Gallic War’, the main source for the conflict -that the attack on Britain was a military necessity. It was not. Reading between the lines and interpreting afresh the evidence Caesar himself provides, we can tell that his judgement was clouded by his yearning for showy success. The story of Caesar’s first attack on Britain is a classic study in how political ambition can get in the way of successful war-making.

Caesar had begun his conquest of Gaul in 58 BC. He had just been appointed governor of the small fragment of Gaul then held by the Roman Empire, equivalent to modern-day Provence, and was eager to make his mark.

Julius Caesar Invasion Of BritainUsing the excuse that migrating Gallic and Germanic tribes might sweep down into Italy and attack Rome, he led his forces deep into non-Roman territory, battling peoples as far north as Belgium.

For the first two years he seemed unstoppable, winning victory after victory. Gallic tribes all the way up the Atlantic coast surrendered without him ever coming near them, and to mark Caesar’s apparent subjugation of the region the Roman Senate voted 15 days of thanksgiving in his honour.

The campaign unravels

At the beginning of 56 BC, everything began to fall apart. Caesar thought he had finished with Gaul, and was already turning his mind to further conquests in Illyricum, modern-day Croatia.

However, beyond taking the children of various Gallic aristocrats hostage and stationing troops across the territory, he had done little to secure Roman power. When the Gauls realised that the Romans had come to stay, they quickly broke into revolt, seizing Roman officers and laying siege to their more vulnerable camps.

Julius Caesar had to stay in Gaul to fight the uprising. It was a much less glamorous business than conquest. Caesar’s men were used to set-piece battles, but at this point they became bogged down in a guerrilla war with Gallic and Germanic tribesmen who struck suddenly and quickly and then retreated into the deep forests and marshes of uncleared wilderness.

This was the context for Caesar’s decision to attack Britain. Frustrated by his loss of momentum, he began to plan a series of dynamic new operations. At first sight, they look sensible: he says that the aim was to cut off external support to the Gallic rebels. But on closer examination they seem to reveal little military purpose – beyond trying to win the applause of the Roman public.

The primacy of politics

De Bello GallicoIt is easy to guess why Caesar might have needed such approval at this point. As the campaign faltered, critics in Rome raised their voices against him. Some quick successes would silence them.

Besides, a desire for conspicuous achievement was at the heart of Caesar’s character. He conveys this himself, in an understated way, when he refers repeatedly in De Bello Gallico to his ‘customary success’.

The Roman historian Suetonius makes the point more vividly. When Caesar was on his first colonial posting to Spain in his early thirties, he saw a statue of Alexander the Great. Beholding it, he wept, thinking that Alexander by his thirties had conquered the known world, while he himself had achieved nothing.

His first such exploit in 55 BC was an assault on the German tribes across the Rhine. He claimed this as necessary to deter them from harassing Gaul.

Caesar was the first Roman general to cross the Rhine, but true glory eluded him. The tribes he had hoped to engage in battle withdrew, leaving Caesar in an exasperating game of shadow boxing. Trying to salvage some credit for the endeavour, he spends more time in De Bello Gallico discussing the technical achievement of a bridge over the Rhine than he does recounting the military events of the campaign.

It was at this point that he turned his attention to Britain.

A wild gamble

Every indication shows that Caesar’s decision to attack Britain was dictated not by military need, but by his desire for a quick and showy success. Two factors should have restrained him.

 tribes of northern GaulThe tribes of northern Gaul were still in revolt, and the summer of 55 BC was drawing to a close. Both factors represented a serious threat to any cross-Channel expedition. The risk was that it would be cut off if rebels seized its Gallic shore ports or autumn storms made the seaway too dangerous.

Caesar dismissed these objections as trifles. What case does he present in De Bello Gallico for attacking Britain so late in the campaigning season? He claims that ‘in nearly all the Gallic campaigns’, Britain had sent help to his enemies in Gaul. He also writes that even though time was running out for a new campaign that year, it would still be useful to cross to Britain to spy out the people and the territory.

Both arguments seem open to doubt. In De Bello Gallico, he only once mentions the possibility that the British might be aiding the Gauls against him. Given this, an intervention across the Channel could hardly have been urgent when Gaul itself was in revolt. Nor does it seem likely that a reconnaissance mission to Britain – one requiring the commander-in-chief’s personal attention and the involvement of a large slice of his army – was a higher priority than Gaul itself.

An exotic bauble

Despite what he says, the only plausible explanation for Caesar’s decision is that the glory of new conquest was preferred over the tedium of counter-insurgency. And it would not be surprising if he had become fixated on Britain.

Not only did the Romans think the island wealthy in slaves, gold, pearls, and tin, but it also had the mystique and challenge of lying on the very edge of their known world. Any general who could even reach Britain with an army would win undying fame. Now that he was within striking distance, it is hardly surprising that Caesar was tempted to risk the security of Gaul for this exotic bauble.

Just as he seems to have deluded himself over the need to attack Britain, so he also seems to have deluded himself over the degree of preparation necessary.

Caesar's decisionThe hastiness of his action suggests a greater interest in glory than military requirements.

His first failing was in intelligence. The Romans had little definite knowledge about Britain. Their geographers could not even agree whether it was actually an island, let alone give reliable information about its size, shape, or harbours.

Caesar first attempted to discover these things by questioning Gallic merchants who made regular voyages there. Unsurprisingly, they refused to tell him anything, no doubt unwilling to have their trade disrupted by warfare or usurped by Roman rivals. Not only did they fail to help Caesar; they informed the British chiefs that he was probably preparing an invasion.

Poor preparation and planning

The British tried to forestall the campaign, sending envoys across the Channel offering to submit. Caesar, in a manner that can only suggest he was deceiving himself for the sake of his plan, took this to indicate that the British were well-disposed, and that a visit to the islands would be less, not more risky.

Needless to say, the British envoys did not tell him anything about the geography of the island. He was compelled to send a ship to scout out the Kent coastline. But this was hardly helpful either. Not only did it fail to pick out some of the best anchorages for large vessels – it located Dover, but not the excellent haven at Richborough – but its captain did not dare explore inland. It was poor reconnaissance for the Romans, but a clear warning to the British.

In a hurry to depart, Caesar was also careless with his preparations. He had assembled 80 transport ships at Portus Itius (Boulogne). This was just enough to carry two legions. However, they had to be packed in tightly. There would have been up to 150 soldiers in each ship, though these are unlikely to have been much more than 20 metres in length. Heavy equipment had to be left behind. Rations were kept to an absolute minimum, so that the Romans would have to rely on foraging when they arrived. Worse, these vessels were high-sided and would be unsuitable for a beach landing.

In every way, Caesar was leaving himself without room for manoeuvre. If he could disembark without opposition in the harbour at Dover, all would be well. If anything went wrong, his force would be dangerously vulnerable.


Caesar embarked his two best legions at Boulogne, the Seventh and the Tenth, late on 24 August 55 BC. However, 18 other vessels, in which he had planned to transport his cavalry, were stuck in a haven six miles up the coast thanks to a contrary wind.

Caesar’s haste again led him to take an excessive risk. Rather than ensuring that his whole force sailed together, he went ahead at midnight with the legions, leaving his cavalry under orders to ride down the coast to where their ships were detained and to embark and follow him as soon as possible.

As morning broke on the morning of 25 August, it became clear to Caesar that his gambles were not paying off. The cavalry were nowhere to be seen: the wind was still detaining them. And when the White Cliffs of Dover came into view ahead, the Roman commander saw a huge host of British warriors ranged along their edge, looking out to sea and awaiting his arrival.

Caesar vesselsHe knew straightaway that his plans were unraveling. There was no way he could bring his large fleet safely into the harbour. The cliffs were so steep and arranged in such a way that the Britons could easily have showered rocks and missiles on the Romans from a great height as they attempted to come ashore.

Caesar realised that his men would have to attempt a beach landing. For this, cavalry would be needed to secure a wide area around any beachhead -but they had still not joined him.

He waited at anchor until three o’clock in the afternoon, and then headed north-east along the coast from Dover, around South Foreland, and then towards the low pebble beach between Walmer and Deal, where the cliffs came down to the shoreline.

Tracking his every move, the British warriors effectively chased the Roman fleet along the coast. Their cavalry and chariots went ahead, and the foot followed close behind. When they realised where Caesar was planning to come ashore, they quickly formed up to oppose him.

The battle on the beach

Everything was now against the Romans. The day had already been long and full of uncertainties, and it was now drawing towards evening. The first close-up sight of the British warriors with their long hair and moustaches, their blue war-paint and gold torques, their numerous fighting chariots – which were, by Caesar’s time, thought to belong to an epic past – must have unnerved the weary Roman legionaries.

Caesar is candid in De Bello Gallico about the difficulties they now faced:

“The size of the ships made it impossible to run them aground except in fairly deep water; and the soldiers, unfamiliar with the ground, with their hands full, and weighed down with the heavy burden of their arms, had at the same time to jump down from the ships, get a footing in the waves, and fight the enemy, who, standing on dry land or advancing only a short way into the water, fought with all their limbs unencumbered and on perfectly familiar ground, boldly hurling javelins and galloping their horses, which were trained to this kind of work. These perils frightened our soldiers, who were unaccustomed to battles of this kind, with the result that they did not show the same alacrity and enthusiasm as they usually did in battles on dry land.”

Caesar’s mistakes had led to this débâcle. But he was a good enough commander to be able to save his men from defeat.

Accompanying the transport ships was a squadron of warships: fast, long, manoeuvrable vessels, perhaps with double ranks of oars. Catapults were mounted on their decks, protected by turrets, and the vessels were filled with auxiliary troops: slingers from the Balearic Isles and archers from Numidia and Crete. Caesar ordered these ships to operate on the enemy’s right flank and bring it under sustained missile-fire.

 Roman legionariesWhen this attack forced the British to draw back a little, it made room for more of the Romans to jump from the side of their transport ships. They were headed by the standard-bearer of the Tenth Legion, who prayed to the gods and then shouted: ‘Jump out, men, if you don’t want to betray your standard to the enemy! At least I’m doing my duty to the Republic and my general.’

As the other soldiers, stirred to action by this call, began to leap out in greater numbers, Caesar ordered smaller scouting-vessels, also with the fleet, to rush to the aid of small groups of soldiers who were struggling in the water and unable to get themselves into orderly ranks. In this way, a sufficient body of men was finally able to make it onto the shore, form up, and mount a decisive charge.

A doomed mission

Even though his men had scattered the British and secured a camping ground, the consequences of Caesar’s over-hasty preparation dogged them. Lack of cavalry was the greatest problem.

They had been unable to pursue the defeated British at the beachhead and turn their first success into a rout. And over the following days, their lack of mobility meant that they could not even carry out the main ostensible purpose of the mission: reconnaissance.

As Caesar had brought only a scanty supply of rations, the soldiers’ time was fully taken up with foraging and defending the camp. Without a proper body of cavalry, this was a trying enterprise. After several days out collecting grain, the Seventh Legion fell victim to an ambush, and Caesar was only just able to rush to their aid with reinforcements and save them from annihilation.

Matters were made yet worse by one final piece of carelessness. Caesar left the main body of transport ships at anchor off the beach, rather than hauling them safely onto land. Around the time of the full moon on 30 August, storms and a high tide combined to smash and wreck a number of vessels.

Caesar had come without the necessary gear to repair his ships, and a fast boat had to be sent to the Continent for tools and materials. The pressure on Caesar’s men increased as their time was now split between foraging, defence of the camp, and repairing the ships.

In the event, Caesar was able to repair all but 12 of the transport ships, allowing him capacity for a full evacuation, but he needed to pack his men in even more tightly for the return voyage.


Caesar escaped before the autumn equinox. By breaking a siege at his camp on the Deal shore before departing, he was able to salvage some honour in retreat. Yet, in every way, the expedition had been a mess. Little had been achieved for an excess of risk and effort. His poor organisation and intelligence-gathering, marred by haste, led him to the brink of disaster. His yearning for an iconic achievement had overwhelmed the patience necessary for sure progress. Problems, such as the secure pacification of north-western Gaul, had been ignored for the whimsy of British conquest.

But there is a final twist – as Caesar is at pains to tell us. Military failure was transformed into political triumph. The mere fact that Caesar had been able to lead Roman legions to the fabled land of Britain caused a huge outpouring of national excitement.

For his initial victories in Gaul, the Senate had voted Caesar 15 days of thanksgiving. But just for reaching Britain and staying there less than a month, with nothing in the way of substantive achievement, he was voted 20 days of thanksgiving.

Even in Roman times, it could be easier for a commander to succeed by simply manipulating the public’s obsession with hollow jingoism than by winning a concrete victory. Author: Bijan Omrani www.bijanomrani.com