Once the Romans had control of the country, they tried to work with the leaders of the tribes they had defeated. But they were often very heavy handed, especially as they were not used to dealing with women rulers.
Boudicca (also spelled Boadicea) was a British queen of the Iceni tribe, but the Romans tried to take her land and depose her. So in AD 60 she rallied people whose lands had also been seized and started a rebellion…