Under the traditional model, William I took all the land in the realm into his ownership3 and granted estates, known as fiefs, to his greater followers to hold from him as ‘tenants-in-chief’. These owed the king homage and fealty-personal loyalty-together with the military service due in respect of their land. The tenantsin-chief then granted portions of that land to their own followers-their vassalsin return for homage and fealty, reserving that due to the king. Military service was owed only to the king, so that vassals of the tenants-in-chief were not obliged to serve their lords in rebellion. The tenants-in-chief fulfilled their military obligations not only by serving the king personally, but also by making their vassals available to serve in his armies. In practice, feudal landholders led retinues composed of their vassals in the service of the king when called upon. In addition to homage, fealty and military service, a feudal lord was entitled to receive payments known as ‘reliefs’ from his vassals on occasions such as the knighting of their eldest sons and the marriage of their eldest daughters, and when an heir came into possession of a fief. He was further entitled to payments known as ‘aids’ on the knighting of his own eldest son and the marriage of his eldest daughter.