In the aftermath of the Conquest in 1066, William the Conqueror and his followers locked castles into the political and economic fabric of the realm through a system of territorial endowment. At its simplest, this took the form of an estate - variously termed an honour (or honor), a rape or a castlery - of which the produce, revenue and labour were directed to sustain a castle at its focus. One of the most important labour contributions of the estate towards the castle was a system of knight’s service, by which individuals received parcels of land in return for military duty including garrison service.
Two methods of fortification are commonly associated with castles in this period. The first was the construction of a ditched enclosure or bailey with a stone wall or timber palisade. Often additionally erected in combination with a bailey was a high tower, a feature without obvious precedent in English domestic architecture. Such towers might be built in varying combinations of earth, stone and timber. As the material of Roman monumental architecture, stone enjoyed particular prestige. In their architecture the Normans carefully copied Roman forms, hence the descriptive name of their building style as Romanesque.