Caesar In Britain: What Happened When He Crossed The Channel?

Britain was known to the Classical World as a source of tin and the edge of the known world. Read more about Caesar in Britain during the Gallic Wars.

Dec 3, 2020By Robert C. L. Holmes, MA Ancient & Medieval History, BA Archaeology
caesar in britain battersea shield
The Battersea Shield, 350-50 BC; with Celtic Sword & Scabbard, 60 BC; and Silver Denarius depicting Venus and defeated Celts, 46-45 BC, Roman


Northeastern Gaul and Britain had been in close contact for centuries and were intertwined economically, politically, and culturally. The Roman general and statesman, Julius Caesar claimed in his writings that the Britons had supported the Gauls in their attempts to resist his forces. During the Roman invasion, some Gauls had escaped to Britain as fugitives, while some Britons had crossed the channel to fight on behalf of the Gauls. As such, late in the summer of 55 BC, Caesar made the decision to launch an invasion of Britain. Intelligence concerning the island was gathered from local merchants and by sending out a scout ship, while ships and soldiers were gathered and negotiations were carried out between the Romans and ambassadors from various British tribes. Yet despite these preparations, and the presence of Caesar in Britain, neither of these invasions were intended to permanently conquer the island.


Caesar Arrives: Landing in Britain 

silver coin caesar in britain neptune
Silver coin with symbols of Neptune and a warship, 44-43 BC, Roman, via the British Museum, London


During the first landing of Caesar in Britain, he and the Romans initially tried to dock at the natural harbor of Dover but were deterred by the large force of Britons that was massed nearby. The Britons had gathered on the nearby hills and cliffs overlooking the beach. From there, they could have rained down javelins and missiles on the Romans as they attempted to disembark. After gathering the fleet and conferring with his subordinates, Caesar sailed to a new landing spot 7 miles away. The British cavalry and chariots followed the Roman fleet as it moved along the coast and prepared to contest any landing.


Traditionally, the Roman landing is believed to have taken place at Walmer, which is the first level beach area after Dover. It is here too that the memorial commemorating the landing has been placed. Recent archaeological investigations by the University of Leicester suggest that Pegwell Bay on the Isle of Thanet, in Kent England is the first landing site of Caesar in Britain. Here archaeologists have discovered artifacts and massive earthworks dating to the period of the invasion. Pegwell Bay is not the first possible landing area after Dover, but if the Roman fleet was a large as it was said to be it is possible that the beached ships would have been spread from Walmer to Pegwell bay.


Battle On The Beaches

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Celtic Sword & Scabbard, 60 BC, via The Metropolitan Museum of Art, New York


The heavily loaded Roman ships were too low in the water to get in close to the shore. As a result, the Roman soldiers had to disembark from their ships in deep water. As they struggled ashore, they were attacked by the Britons who easily rode their horses into the deep water. The Roman soldiers were understandably reluctant to jump into the waters until they were goaded into action by one of their standard bearers. Even then it was not an easy fight. Ultimately, the Britons were driven off by catapult fire and sling stones from the warships which were directed into their exposed flanks.

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battersea shield

The Battersea Shield, 350-50 BC, British; with The Waterloo Helmet, 150-50 BC, British, via the British Museum, London


Standards held an important ritual and religious significance to the soldiers of the Romans of the Roman army. A unit that lost its standard to the enemy faced shame and other punitive actions. The men who carried them were also very important and were often also tasked with carrying and disbursing the soldiers’ pay. As such, the soldiers had a vested interest in ensuring the safety of both the standards and the standard bearers. Roman military history abounds with tales of standard bearers putting themselves and the standards at risk in order to motivate the soldiers towards making greater efforts in battle. However, the results produced by such stratagems were mixed.


Stormy Weather On The Channel

pottery beaker gaul britain

Pottery Beaker, made in Gaul and found in Britain, 1st century BC; with Pottery platter in Terra Rubra, made in Gaul and found in Britain, 1st century BC, via the British Museum, London


After the Britons were driven back Caesar established a fortified camp near the beachhead and opened negotiations with the local tribes. However, a storm scattered the ships carrying Caesar’s cavalry forcing them to return to Gaul. Some of the beached Roman ships filled with water, while many of those riding at anchor were driven into each other. The result was that some ships were wrecked, and many others were rendered unseaworthy. Soon supplies in the Roman camp were running low. The sudden Roman reverse did not go unnoticed by the Britons, who now hoped that they could prevent Romans from leaving and starve them into submission. Renewed British attacks were defeated and beaten back in a bloody rout. However, the British tribes no longer felt cowed by the Romans. With winter rapidly approaching, Caesar repaired as many ships as possible and returned to Gaul with his army.


Caesar and the Romans were unused to the Atlantic tides and weather they encountered in the English Channel. Here, the waters were far rougher than anything that Mediterranean people like the Romans were familiar with. Roman warships and transports, which were perfectly suited for the calmer seas of the Mediterranean, were no match for the wild and unpredictable Atlantic. Nor did the Romans know how to safely operate their vessels in these waters. As such, those Romans with Caesar in Britain faced greater challenges from the weather than they did from the Britons themselves.


Caesar In Britain: The Second Invasion 

intaglio roman warship
Intaglio depicting a Roman warship, 1st century BC, Roman, via the British Museum, London


As a reconnaissance in force, the first foray of Caesar in Britain was a success. However, if it was intended as a full-scale invasion or a prelude to the conquest of the island, then it was a failure. The surviving sources are, unfortunately, unclear on the matter. Nonetheless, Caesar’s report of the action was well received by the Senate in Rome. The Senate decreed a twenty-day Thanksgiving to recognize the conquests of Caesar in Britain, and for going beyond the known world to the mysterious island.


Over the course of the winter of 55-54 BC, Caesar planned and prepared for a second invasion. This time he gathered five legions and two thousand cavalrymen for the operation. His most important step, however, was to oversee the construction of ships more suitable for operations in the channel. The Roman fleet was joined by a large contingent of merchant vessels looking to trade both with the Roman army and with the various tribes of Britain. Along with his other motives, Caesar also sought to determine the economic resources of Britain as there had long been rumors that the island was rich in gold, silver, and pearls.


Return Of The Romans

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Coolus Type A Mannheim Helmet, ca. 120-50 BC, Roman, via the British Museum, London


This time the Britons did not seek to oppose the Roman landing, which was made near Dover where Caesar had initially attempted to land the year before. It is likely the size of the Roman fleet intimidated the Britons. Or perhaps the Britons needed more time to gather their forces to face the Roman invaders. Once ashore, Caesar left Quintus Atrius, one of his subordinates in charge of the beachhead, and led a rapid night march inland.


The Britons were soon encountered at a river crossing on what was likely the river Stour. Although the Britons launched an attack they were defeated and forced to retreat to a nearby hillfort. Here, the Britons were attacked and once again defeated, this time being scattered and forced to flee. The next morning Caesar received word that once again a storm had seriously damaged his fleet. Returning to the beachhead, the Romans spent ten days repairing the fleet while messages were sent to the mainland requesting more vessels.


Caesar’s Battle For Britain

golf coin caesar horse
Gold Coin with Horse, 60-20 BC, Celtic Southern Britain, via The British Museum, London


Caesar in Britain now faced resistance which coalesced around Cassivellanus, a powerful warlord from north of the Thames river. Several indecisive skirmishes with the Romans were followed by a massive attack on three of the Roman legions while they were out foraging. Caught off guard, the legions were only able to fight off the British attack thanks to the intervention of the Roman cavalry. Cassivellanus now realized that he could not defeat the Romans in a pitched battle. Therefore, he dismissed most of his forces except for his elite charioteers. Relying on the mobility of this 4,000-man force, Cassivellanus waged a guerrilla campaign against the Romans hoping to slow their advance.


These attacks slowed the Romans enough that by the time they reached the Thames they found the only possible fording place heavily defended. The Britons had placed sharpened stakes in the water, erected fortifications on the opposite bank, and gathered a sizable army. Unfortunately, the sources are unclear as to how Caesar managed to get across the river. A much later source claims that he employed an armored elephant, though where he procured it is unclear. It is far more likely that the Romans made use of their superior armor and missile weapons to force their way across. Or internal dissension may have split Cassivellanus’ coalition. Prior to the Roman invasion, Cassivellanus had been at war with the powerful Trinovantes tribe who now supported Caesar.


Caesar Crushes Cassivellanus’ Coalition

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Silver Denarius depicting Venus and defeated Celts, 46-45 BC, Roman, via the British Museum, London


With the Romans now north of the Thames more tribes began to defect and surrender to Caesar. These tribes revealed to Caesar the location of Cassivellanus’ stronghold, possibly the hillfort at Wheathampstead, which the Romans quickly besieged. In response Cassivellanus’ sent word to his remaining allies, the Four Kings of Cantium, requesting that they come to his aid. British forces under their command launched a diversionary attack on the Roman beached which, it was hoped, would convince Caesar to abandon his siege. However, the attack failed and Cassivellanus was forced to sue for peace.


Caesar was, himself, eager to return to Gaul before winter. Rumors of growing unrest in the region gave him cause for concern. Cassivellanus was forced to provide hostages, agree to an annual tribute, and refrain from waging war against the Trinovantes. Mandubracius, the son of the previous king of the Trinovantes, who had been exiled after the death of his father at the hands of Cassivellanus was restored to the throne and became a close Roman ally.


The Legacy Of Caesar In Britain

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Blue glass ribbed bowl, 1st century, Roman, found in Britain, via the British Museum, London


In his correspondence, Caesar mentions the many hostages brought back from Britain but makes no mention of any booty. The relatively short campaign and subsequent evacuation of Roman forces from the island precluded the usual extensive looting the followed such a campaign. Roman forces were so completely removed from the island due to the mounting unrest in Gaul that not a single soldier remained. As such it is unclear if any of the agreed-upon tribute payments were ever made by the Britons.


What was found by Caesar in Britain in great quantities was information. Prior to the invasion, the island of Britain was relatively unknown to the various civilizations of the Mediterranean. Some had even doubted the island’s very existence. Now, Britain was a very real place. The Romans were henceforth able to make use of the geographic, ethnographic, and economic information that Caesar brought back to establish trading and diplomatic relations with the Britons. Caesar may never have returned to Britain due to uprisings in Gaul and civil war in Rome, but the Romans certainly did as Britain became the northernmost province of their empire.

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By Robert C. L. HolmesMA Ancient & Medieval History, BA ArchaeologyRobert Holmes has an MA in Ancient & Medieval History and a BA in Archaeology. He is an independent historian and author, who specializes in the Military History of the Ancient and Medieval World and has published over a dozen articles on related topics. Originally from Massachusetts, he now lives in Florida where he works doing public history leading tours, giving lectures, and educating people about the local history.