Boudica was a queen of a Celtic tribe who led an uprising of the tribes against the occupying forces of the Roman Empire.

Boudica's husband, Prasutagus, ruler of the Iceni who had ruled as a nominally independent ally of Rome, left his kingdom jointly to his daughters and the Roman Emperor in his will. However, when he died his will was ignored. The kingdom was annexed as if conquered, Boudica was flogged and her daughters raped, and Roman financiers called in their loans.

In AD 60 or 61, while the Roman governor, Gaius Suetonius Paulinus, was leading a campaign on the island of Anglesey in north Wales, Boudica led the Iceni people, along with the Trinovantes and others, in revolt. They destroyed Camulodunum (Colchester), formerly the capital of the Trinovantes, but now a colonia (a settlement for discharged Roman soldiers) and the site of a temple to the former emperor Claudius, which was built and maintained at local expense. They also routed a Roman legion, the IX Hispana, sent to relieve the settlement.

On hearing the news of the revolt, Suetonius hurried to Londinium (London), the twenty-year-old commercial settlement that was the rebels' next target. Concluding he did not have the numbers to defend it, Suetonius evacuated and abandoned it. It was burnt to the ground, as was Verulamium (St Albans). An estimated 70,000--80,000 people were killed in the three cities.

Suetonius, meanwhile, regrouped his forces in the West Midlands, and despite being heavily outnumbered, defeated the Britons in the Battle of Watling Street. The crisis caused the emperor Nero to consider withdrawing all Roman forces from the island, but Suetonius' eventual victory over Boudica secured Roman control of the province. Boudicca then killed herself so she would not be captured, or fell ill and died, Tacitus and Dio differ.