Roman Britain: Caesar's Invasions (55-54 BC)

The White Cliffs of Dover - The Battle on the Beachhead - The Wreck of the Fleet -

Retreat to Gaul - An Unopposed Landing - The Fight on the Stour River -

The Crossing of the Thames - A Deal with the Trinovantes - The Surrender 

of Cassivellaunus - Caesar's Triumphant Evacuation of Britain

Julius Caesar is known for his “Gallic Wars” (his wars against the native tribes of what is modern-day France and Belgium), but lesser known are his two failed invasions of Britain. Perhaps they’re lesser known because they were failures, though Caesar made them into “explorations” when it came to his expertly-woven self-propagandizing. As a pretense for his first invasion, Caesar claimed that Britons had assisted the Gauls by giving them refuge in Britain and by assisting the Veneti of Armorica (modern-day Brittany) against him. Caesar began planning his first invasion in the summer of 55 BC. The British tribes got wind of it and sent delegates to Gaul to promise their submission. Caesar accepted their submission and sent them back across the Channel with the king of the Gallic Atrebates tribe, Commius, in the hope that he could win over further tribes to the Roman cause.

Roman troops approach the beachhead

In August of 55 BC Caesar set out with two legions (Legio VII and Legio X) with his cavalry instructed to follow after them. Caesar had wanted to land along the modern-day White Cliffs of Dover, but when his fleet came into sight of the cliffs, they saw Briton warriors amassed upon them; fearing that the Britons would rain missiles on his troops, he sailed seven miles along the coast to an open beach. The British forces had tracked their route from the cliffs, and Caesar’s landing was opposed by British foot soldiers and charioteers. Because the Roman transports were too low in the water to reach the shore, the Roman soldiers had to wade onto dry land. The British fought against the troops while they were in the water, but Roman catapults and slings, fired from the warships, pushed the British back. The Romans were able to take the beachhead, and the British scattered inland; but because Caesar’s cavalry had yet to arrive, the enemy’s retreat couldn’t be turned into a rout.

Romans fighting offshore against the Britons

Caesar built a camp on the beach and welcomed delegates from the British tribes. Commius, who had been imprisoned upon his arrival to Britain, was returned to him. The British leaders insisted that Caesar’s beachfront battle had been due to the spirit of the commoners rather than from their leadership, and the leaders offered Caesar hostages and disbanded their own troops. Caesar’s fortunes turned, however, when the high tide (which was altogether different from Mediterranean tides), coupled with an awful storm, sank or crippled a number of his transport ships at anchor off the beach. The British realized Caesar was at a disadvantage, since his return journey to Gaul was threatened, and they reinitiated their attacks, hoping to weaken and starve him out during the coming winter. British warriors ambushed one of the legions as it foraged close to the Roman camp. The ambushed troops were relieved by their brethren from the Roman camp, but the British amassed a larger force and attacked again. This time the British fared far worse, for the Romans had gathered a ragtag force of cavalry thanks to Commius’ conniving with pro-Roman Britons and horses stolen from the local countryside, and the British, bloodied and beaten, fell back. The British leaders sent more delegates and Caesar demanded double the number of hostages, but he knew that if he couldn’t get out by winter, his army would be doomed to a harsh winter of guerrilla warfare and starvation. Patching the wrecked and flooded ships as best he could, Caesar abandoned his camp and returned to Gaul.

Caesar wasn’t one to give up easily, and he planned a second invasion with a much larger force: five legions instead of two, plus a contingent of over 2000 cavalry. He also ordered construction of a different type of vessel more suitable for beach landing, copying the technology of the Veneti whose naval vessels were designed for the choppy and unpredictable seas of the Channel. Caesar’s landing was unopposed, perhaps because the Britons feared the size of Caesar’s fleet. Immediately after landing Caesar ordered a night march and took a large force twelve miles inland where they made their first contact with the enemy at a river crossing, probably on the Stour River. The Britons were repulsed and fled to a nearby hill-fort. Caesar defeated them there, too, but now it was late the next day and he ordered a camp to be built.

Roman troops versus Briton warriors

Next morning Caesar received news from the beachfront camp that another storm had struck and damaged a number of his transports. Caesar turned his force around and marched them back to the beachhead. Ten days and nights were spent both repairing the damaged vessels and fortifying the beachfront camp. He requested more ships from Gaul and marched back to the Stour River, where the Britons had amassed themselves once again to thwart his river crossing. The Britons were led by a warlord named Cassivellaunus, who hailed from north of the Thames; Cassivellaunus had been at war with a number of British tribes for some time, but he had recently overthrown his chief rival, the Trinovantes, and the Britons had appointed him as their leader against the Romans. The Britons waged a number of indecisive skirmishes, and Cassivellaunus knew they lacked the prowess to defeat the professional Roman soldiers in a pitched set-piece battle. He disbanded most of his forces and relied on the mobility of his 4000 charioteers for strike-and-run tactics against the Romans, who were steadily advancing towards the Thames River. When Caesar reached the Thames, the one possible fording spot had been defended with sharpened stakes, and British warriors crowded the far bank. Legend has it that Caesar employed a war elephant equipped with armor and topped with archers and slingers in its tower to frighten the British away from the crossing. When the elephant, formerly unknown to the British, entered the river, the British horses panicked and the foot soldiers followed suit. The Romans then crossed the Thames and entered Cassivellaunus’ territory.

A Rendition of Cassivellaunus

Now politics played in the Romans’ favor. The Trinovantes, formerly known as the most powerful of British chiefdoms, had been humiliated by Cassivellaunus, and the Trinovantes’ ruler, Mandubracius, had been sent into exile. Mandubracius curried favor with Caesar, promising submission to Rome, if he would help him against Cassivellaunus. Caesar agreed, restoring Mandubracius to the Trinovantian throne. The Trinovantes, in return, provided Caesar’s forces with much-needed grain. Following the example of the Trinovantes, five further British tribes—the Cenimagni, Segontiaci, Ancalites, Bibroci, and Cassi—surrendered to Caesar and fed him information about Cassivellaunus’ whereabouts. Caesar marched on Cassivellaunus’ stronghold and laid siege. Cassivellaunus’ allies staged a diversionary attack on the beachhead to pull Caesar away from the stronghold, but the attack failed. Cassivellaunus was left only with the hope of diplomacy, and Caesar took the bait, eager to return to Gaul before the coming winter. Cassivellaunus surrendered, giving hostages, agreeing to an annual tribute, and promising not to wage war against Mandubracius of the Trinovantes. Caesar then left Britain, taking every Roman soldier with him, and it’s unknown if Cassivellaunus ever kept his word on his promises to Caesar.