Cartimandua was a client Queen to the Romans, who did betray Caratacus. It was her estranged husband Venutius who led the rebellion against Rome. The tale has it that Cartimandua captured a number of Venutius' relatives and sought refuge at Castle Hill (Camulodunum) in Almondbury, Huddersfield (although this is very likely untrue and an invention of historians as Castle Hill was abondoned around 400BC) and that Venutius was finally defeated at Stanwick Camp in North Yorkshire after building Ingleborough.
Guy Ragland Phillips' book 'Brigantia' has many a good folktale.