By 1086 William the Conqueror and the first generation of Anglo-Norman magnates had laid the foundations of Norman rule in Yorkshire. The county had undergone a social, military and (in places) tenurial revolution. The vast majority of the Anglo-Scandinavian aristocracy had been deprived of their lands or demoted to the level of subtenants, their governmental offices had been taken away, their honours had been partially reorganised and many of their most important administrative and population centres had been subjected to Norman military control. The county probably bristled with Norman castles, around the majority of which a resident continental tenantry was already bringing Norman administration to bear. And coordinating this administration was the Norman sheriff, based in one of the castles at York, and directly responsible to the king.

In the years that followed the Conqueror's death in 1087 it fell to his sons, William Rufus and Henry I, to build upon these tenurial, military and administrative foundations in order to consolidate and extend the Norman grip on Yorkshire. There remained much to be done. The large areas of the county which lay outside direct Norman control, such as Cleveland and the eastern fringes of the Pennines, required organisation and colonisation. If the Normans were going to exercise effective royal control of Yorkshire, it was also imperative that the local administration be developed and brought under the closer supervision of central government.