Norman Conquest Encyclopedia
The Anglo-Saxon thegn held his land, bocland , by book-right. His title was a matter of written record and the inheritance of that holding by his successors was virtually guaranteed. In return he owed to his lord fyrd service (military service), burhbot (service in burh repairs, i.e. repairing fortifications) and brycgeworc (bridge-work or bridge repairs). Other services might, in given circumstances, be required such as funding ships, organising the raising of the local fyrd, maintaining the fencing of the lord's estate, and so forth. His social senior was the earl or ealdorman and his immediate inferior the ceorl.