The castle was first constructed in approximately 1070 by Ilbert de Lacy on land which had been granted to him by William the Conqueror as a reward for his support during the Norman conquests. There is, however, evidence of earlier occupation of the site. Initially the castle was a wooden structure, but this was replaced with stone over time.[2] The Domesday Survey of 1086 recorded "Ilbert's Castle" which probably referred to Pontefract Castle.[3]