The Saxons introduced ‘Hundreds’ for military and judicial purposes, geographical divisions of the Sheriff-controlled ‘Shire’. In Sussex, ‘Rapes’ may represent the ancient shires, or the late 9th Century system of fortifications introduced by King Alfred.
In 1086, the ‘honour’ bestowed by William the Conqueror to reward the services of Earl Roger de Montgomery resulted in the Arundel Rape holding most land in West Sussex. His broader English land holdings yielded about 3% of the entire national income; now GDP. One of the most important parts of the ‘Honour’ bestowed by the King was the Forest and Chase of Arundel.
More of the Slindon and Arundel in the published book.
Part 1 here