Roman Conquest of Britain (AD 43): Claudius's Invasion

The Roman conquest of Britain began in AD 43, when the emperor Claudius sent an army of four legions under Aulus Plautius across the Channel. Within months the invaders had defeated the leading British kingdom and captured its capital at Camulodunum (Colchester), where Claudius himself received the surrender of British rulers. It was the start of the Roman province of Britannia, which lasted for nearly four centuries.

Background

Britain was not unknown to Rome. Julius Caesar had crossed the Channel twice, in 55 and 54 BC, defeating the British leader Cassivellaunus but leaving no garrison (see Caesar’s invasions of Britain). Over the following century southern Britain was drawn into Rome’s orbit by trade, diplomacy and imported luxuries such as wine and fine pottery.

Augustus considered an invasion several times but never launched one. In AD 40 Caligula marched an army to the Channel coast and then abandoned the attempt. Britain was a tempting goal: it was believed to be rich in metals, grain and slaves, and conquering the land beyond the “Ocean” carried enormous prestige.

The pretext

In south-east Britain the most powerful kingdom belonged to the Catuvellauni, ruled for decades by Cunobelinus (Shakespeare’s Cymbeline). From his capital at Camulodunum he extended his power over neighbouring peoples. After his death, around AD 40, his sons Togodumnus and Caratacus continued this expansion.

Around AD 41–42 they drove out Verica, king of the Atrebates in the area of modern Hampshire and Sussex, who was an ally of Rome. Verica fled to Claudius and asked for help. For Claudius, who had been made emperor by the Praetorian Guard after the assassination of Caligula, this was an opportunity. He lacked military glory and had faced an attempted revolt in AD 42; a conquest would strengthen his authority.

The invasion force

The army assembled at Boulogne (Gesoriacum) under Aulus Plautius, the governor of Pannonia. It included four legions: II Augusta, commanded by the future emperor Vespasian, IX Hispana, XIV Gemina and XX. With auxiliary infantry and cavalry, the total is usually estimated at around 40,000 men.

According to Cassius Dio, the soldiers at first refused to embark, fearful of sailing beyond the known world. Claudius’s freedman Narcissus tried to address them, and the troops mocked him as a former slave. The mutiny collapsed, and the army sailed in three divisions, probably in the summer of AD 43.

Landing and the river battles

Most historians place the main landing at Richborough (Rutupiae) in east Kent, where archaeologists have found defensive ditches from the 40s AD. An alternative theory proposes landings near Chichester, in the territory of Verica’s people. The Britons did not oppose the landing, apparently expecting the Romans to turn back as before.

Plautius first defeated Caratacus and then Togodumnus in separate skirmishes. The decisive clash came at a river crossing, usually identified with the Medway in Kent. Dio describes a hard fight lasting two days: Celtic auxiliaries swam the river to attack the British chariot horses, and Vespasian’s troops forced a crossing. A commander named Gnaeus Hosidius Geta won special honours for his part.

The Britons fell back to the Thames, where the Romans again crossed and pursued them. Togodumnus died soon afterwards. Plautius then halted, as planned, and sent for the emperor.

Claudius in Britain

Claudius travelled from Rome by river and sea, bringing reinforcements that reportedly included elephants. He joined the army at the Thames, led the advance on Camulodunum and captured it. Suetonius says he spent only 16 days in Britain before returning to Rome.

A triumphal arch dedicated in Rome in AD 51–52 records that Claudius received the surrender of eleven British kings without loss. He celebrated a magnificent triumph in AD 44, and his young son took the name Britannicus in honour of the victory. Plautius stayed on as the first governor of Britannia until AD 47.

Conquest of the south and west

The conquest did not end with Camulodunum. Vespasian led Legio II Augusta into the south-west. Suetonius credits him with fighting thirty battles, defeating two powerful tribes, capturing more than twenty hill forts and taking the Isle of Wight. Excavations at hill forts such as Hod Hill and Maiden Castle in Dorset show Roman attacks or occupation in these years, though the famous “war cemetery” at Maiden Castle is now interpreted more cautiously.

Some peoples became allies rather than enemies. Rome recognised client rulers such as Togidubnus (or Cogidubnus) in the south, Prasutagus of the Iceni in East Anglia and Queen Cartimandua of the Brigantes in the north. These arrangements spared Roman troops but proved fragile.

Togidubnus is the best documented of them. An inscription found at Chichester names him as a “great king” in Britain who held Roman citizenship, and Tacitus says he remained loyal to Rome within living memory of the historian’s own day. The lavish Roman-style palace at nearby Fishbourne, begun in the AD 70s, is often linked to him, although that connection cannot be proved.

Resistance and the first frontier

Caratacus escaped west and led resistance among the Silures and Ordovices of Wales. The second governor, Publius Ostorius Scapula (AD 47–52), disarmed suspect tribes, which provoked a first revolt among the Iceni in AD 47. In AD 49 a colony of veteran soldiers was founded at Camulodunum.

Ostorius finally defeated Caratacus around AD 50–51. The British leader fled to Cartimandua, who handed him over to Rome; Claudius famously spared him after a dignified speech in Rome (see Caratacus’s resistance to Rome). By then the Romans held much of lowland Britain, roughly south and east of a line marked by the road later called the Fosse Way.

Consequences

The new province brought roads, towns, forts and trade. Londinium (London) grew rapidly as a port at the lowest practical crossing of the Thames. Yet the conquest also brought heavy taxation, land seizures and forced recruitment, grievances that exploded in Boudica’s revolt of AD 60 or 61.

Archaeology shows the speed of the change. Military supply bases such as those at Richborough and Fishbourne appeared in the first years, followed by a network of forts and roads that allowed troops to move quickly. Coins, pottery and other imports spread rapidly into the conquered areas, while some British communities kept much of their earlier way of life for generations.

Roman control later advanced north under governors such as Agricola, and was finally limited by frontier works including Hadrian’s Wall. Britannia remained part of the empire until the early 5th century.

Timeline

• 55 and 54 BC: Julius Caesar’s two expeditions to Britain.
• AD 40: Caligula’s planned invasion is abandoned.
• c. AD 41–42: Verica of the Atrebates flees to Rome.
• Summer AD 43: Aulus Plautius lands, probably at Richborough, and wins the river battles.
• AD 43: Claudius arrives and captures Camulodunum.
• AD 44: Claudius celebrates his British triumph in Rome.
• AD 47: First Iceni revolt; Ostorius Scapula becomes governor.
• AD 49: Veteran colony founded at Camulodunum.
• c. AD 50–51: Caratacus is defeated and handed over to Rome.

Why it matters

The Claudian invasion turned Britain from a distant island known through traders into a Roman province. It reshaped the landscape with roads, towns and a new capital at London, and it began nearly 400 years in which Britain was part of a Mediterranean empire.