When Sibella , the great - granddaughter of the Norman leader Strongbow , was granted the manor in 1219 , the local Brennan chiefs retreated to the hills and lived an independent life until the plantation of Castlecomer by Earl Strafford .
When Sibella , the great - granddaughter of the Norman leader Strongbow , was granted the manor in 1219 . 
 The local Brennan chiefs retreated to the hills and lived and independent life until the plantation of Castlecomer by Earl Strafford .