What sparked Boudicca's rebellion?
Boudicca's husband was Prasutagus, a Celtic tribal leader and client to the Roman Empire. When he died, according to Celtic custom he left half of his lands to Rome and, not having any male heirs, the other half to Boudicca. Unfortunately, Roman law did not recognize the will, because Boudicca was a woman, and so the Romans claimed the entire domain for themselves. Boudicca publicly defied the Romans, which led to her family being severely punished, but her subjects the Iceni and other Celtic leaders rallied to her side. Many of them were angry at having their lands appropriated by Roman leaders. They were also angry at being disarmed by the Romans, a measure taken to ensure the security of the Roman legions busily suppressing Druid leaders in Wales. Essentially, then, the cause of the revolt was dissatisfaction with the client-kingship relationship negotiated after the conquest of the Island by the Romans.
Boudicca and her followers formed a formidable force. They attacked and destroyed garrisons and civilian populations at Camulodunum (modern Colchester), Londinium (modern London), and slaughtered an entire Roman garrison at Verlanium (modern St. Albans). After a period of very bloody fighting and a number of civilian deaths, Boudicca and her followers were finally trapped and defeated in the Midlands in 62 c.e.. She committed suicide to avoid falling into Roman hands.