Medieval Fuedalism
Feudalism granted landowning Barons the right of jurisdiction and heredity over land granted them and made up of several Manors that effectively began the system of British peerage. For the lower classes it created a class system of slaves, serfs, cottars, villeins and freemen. The lowly of the low, barely above a slave was a cottar, a farm labourer with a smallholding. Though slaves now made up smaller proportion of the population (9% according to the Domesday Book), the majority were reliant on the land and had to make the rent as well as surviving. Being a slave meant you might be beaten, but you were provided for. For some slavery must have seemed a better option than being a free man.
William, who was illiterate, then raised the stakes on class distinction by insisting that legal documents should be written in Latin replacing the Old English Anglo-Saxon and that the Elite speak Anglo-Norman, a dialect of Old French relieving him of the problem of learning Anglo-Saxon.