An army of four legions and approximately 20,000 auxiliaries, commanded by senator Aulus Plautius, landed at Richborough, Kent. The Romans met a large army of Britons, under the Catuvellauni kings Caratacus and his brother Togodumnus, on the River Medway, Kent. The Britons were defeated in a two-day battle, then again shortly afterwards on the Thames. Togodumnus died and Caratacus withdrew to more defensible terrain to the west.

Following the initial invasion of Britain, the Roman emperor, Claudius, arrived to symbolically lead his army to victory. In August, the Romans captured Camulodunum (Colchester), the capital of the powerful Catuvellauni tribe. With the whole of south east Britain overrun, eleven British kings made their submission. Aulus Plautius, commander of the invasion force, was appointed first Roman governor of Britain, but the majority of the island would not be pacified for at least another 50 years

In the second phase of the conquest of Britain, Roman general Vespasian (Titus Flavius Vespasianus - a future emperor) led his II Augusta Legion into Dorset. He fought numerous small-scale battles and captured a string of hill forts, including Maiden Castle and Hod Hill. By 48 AD, the Romans had effectively subdued all territory south of a line from the mouth of the Humber river to the Severn Estuary.

Aulus Plautius led the Roman invasion of Britain in 42 AD and served as governor of the new province until 47 AD when he returned home to Rome. He was replaced by Publius Ostorius Scapula. Plautius was granted an 'ovatio' - a lesser form of military 'triumph' - during which he walked to the Capitol in the company of the emperor, Claudius.

The Iceni tribe (based in East Anglia) were allies of Rome and had not been conquered. When ordered to surrender their weapons by the new Roman governor, Publius Ostorius Scapula, some tribesmen resisted. The revolt was quickly put down. The Iceni remained independent, but it seems likely that the pro-Roman king, Prasutagus, was installed at this time.

With many legionaries due for retirement, the Romans founded a colony for veterans at Camulodunum (Colchester). Barrack-blocks were converted into private houses, public buildings were erected and work was begun on a temple to the imperial cult. Local land was confiscated and parcelled up to make farms for the veterans. Colchester briefly became the capital of the province of Britain.

Following his defeat in the initial phase of the Roman invasion, Caratacus, the king of Catuvellauni, had fled west to first the Silures, then the Ordovices tribes (in Gloucestershire and Wales). He fought an effective guerrilla war, but was eventually brought to battle and defeated by the Roman governor Publius Ostorius Scapula. He escaped, but was betrayed by the Brigantes tribe and captured. He was nonetheless allowed to live out his days in retirement in Italy.

Following the capture of Caratacus, who had led the opposition to Rome in the west of Britain, the Silures tribe (in south Wales and Gloucestershire) fought on. Governor Publius Ostorius Scapula had died in 52 AD, apparently worn out by the stress of office. The conflict fizzled out under his successor, Aulus Didius Gallus. But in 58 AD, a new Roman governor, Quintus Veranius Nepos, finally crushed the Silures and pacified the region with a network of roads, forts and garrisons.

The druids were the priest-scholars of ancient Britain, but 'druid' also tended to be a 'catch all' name used by the Romans for those who resisted their rule. In order to suppress the druids in the far west of Britain, Roman governor Gaius Suetonius Paulinus subdued the island of Mona (Anglesey), but he was forced to cut short the campaign to put down the revolt of the Iceni under Boudicca in south east Britain.

The Romans annexed the territory of the Iceni (in East Anglia) after the death of the tribe's king, Prasutagus. It sparked a rebellion, led by his widow Boudicca, that erupted across south east Britain. The Roman towns of Camulodunum (Colchester), Londinium (London) and Verulamium (St Albans) were burned and thousands killed. Boudicca was eventually defeated by a vastly outnumbered Roman army under governor Gaius Suetonius Paulinus at the Battle of Watling Street. She died soon afterwards.

With the death of the emperor Nero in June 68 AD, four emperors followed in rapid succession - Galba, Otho, Vitellius and Vespasian. Vespasian, who had led a legion during the conquest of Britain, emerged victorious to found the Flavian dynasty. With mutinies and uprisings rife across the empire, the military estate of Britain was no different. But no attempts to become emperor were launched from the province.

The Brigantes tribe of (in northern England) was a Roman ally ruled by Cartimandua and her consort, Venutius. Cartimandua had been responsible for handing over resistance leader Caratacus to the Romans in 51 AD. Shortly afterwards, she divorced Venutius who revolted but was driven off by Roman arms. But in 69 AD, with the Romans in the midst of civil war, Venutius staged a second revolt and successfully overthrew Cartimandua, who fled to the Romans.

After ten years of comparative peace, Vespasian, first emperor of the new Flavian dynasty, ordered further conquests in Britain. The new governor, Quintus Petilius Cerialis, campaigned against Venutius, rebel leader of the Brigantes tribe, and defeated him. By the end of Cerialis' governorship in 74 AD, he had reached Carlisle where he built the last in a series of garrison forts.

Sextus Julius Frontinus was appointed governor of Britain in 74 AD. After three years' campaigning - first against the Silures (in south east Wales) and then against the Ordovices (in north Wales) - he had all but completed the conquest and occupation of western Britain. The territory was pacified by placing auxiliary forts on the hills linked by roads. Two legions, one at Caerleon in the south east and the other at Chester in the north east, could respond quickly to any uprising.

Taking advantage of a change in governor, the recently-conquered Ordovices tribe (in north Wales) revolted. The new governor, Gnaeus Julius Agricola, immediately led an army into their territory and crushed them. He then invaded the island of Mona (Anglesey), effectively destroying the last major druidic centre. The druids left no written texts, but it is known that they were probably animists who practised human sacrifice and may have acknowledged well in excess of 400 gods.

Marking the emergence of a fully-fledged, self-governing municipality, the opening of the Verulamium (St Albans) civic centre was an event of pomp and ceremony attended by the provincial governor Gnaeus Julius Agricola. The new complex comprised a square (forum) with colonnaded shops, an assembly room with adjoining council offices (basilica) and official cult temples. It became one of the biggest and richest towns in Roman Britain.

In a bid to do away with the Britons' warlike ways, Roman governor Gnaeus Julius Agricola undertook a campaign to encourage native aristocrats to learn Latin, wear the toga and invest in budding municipalities by donating statues and buildings. Archaeological evidence suggests Romanisation was swift. By the late first century AD, south east Britain had filled with Roman-style towns and villas.

Having subdued what is now south west Scotland, Roman governor Gnaeus Julius Agricola considered an invasion of Ireland. Agricola reputedly believed a single legion plus auxiliaries (about 10,000 men) would suffice and may even have given refuge to an exiled Irish prince as a pretext for the attempt. The invasion never happened, but regular trading contacts began to develop between Ireland and Roman Britain.