According to the Historia Ecclesie Abbendonensis (Abingdon Chronicle),[1] Oxford Castle was built by the Norman baron Robert D'Oyly the elder from 1071 to 1073.[2] D'Oyly had arrived in England with William I in the Norman Conquest of England and William the Conqueror granted him extensive lands in Oxfordshire.[2] Oxford had been stormed in the invasion with considerable damage, and William directed D'Oyly to build a castle to dominate the town.[3] In due course D'Oyly became the foremost landowner in Oxfordshire and was confirmed with a hereditary royal constableship for Oxford Castle.[4] Oxford Castle is not among the 48 recorded in the Domesday Book of 1086, but not every castle in existence at the time was recorded in the survey.[5] D'Oyly (d'Oilly)'s Oxford holdings are, however, mentioned in the Domesday Book as "Meadow 30 acres.