One of the immediate effects of the completion of the Conquest was the introduction into England of Norman feudalism. By this system the whole country (except what was given to the Church) was handed over to tenants in chief or great vassals, who held their lands in fee and in perpetuity direct from the Crown, in return rendering what was known as knight's service, every estate of £20 a year being considered a knight's fee, and liable to furnish for the King one mounted soldier; the vassals or under-tenants of these barons, or _tenants in capite_, were bound by an oath of allegiance not only to the King, but also to the owner of the fee. These sub-tenants would in many cases consist of such of the Saxon settlers as had not been expelled by the Norman ruler; doubtless many of the great Saxon Thanes on losing their land were expelled from or of their own will left the country. A detailed account of the various changes in the ownership of the soil would here be out of place, but it should be noticed that all the land in private holdings shortly after the Conquest passed into fresh hands--that is, as far as regards the tenure in fee direct from the Crown. After the final defection and consequent banishment of Roger de Poictou in 2 Henry I. (1101-2), West Derby Hundred went to the King, and remained in royal hands until Stephen granted it to Henry, Duke of Normandy; Leyland passed to King John (1199-1200); Blackburn had been bestowed by the Conqueror on Ilbert de Lacy, who came over with him from Normandy; Salford passed through several hands to the Earl of Chester; Amounderness went to the Crown, and was by Henry I. or Stephen presented to Theobald Walter, son of Herveus, another Norman chief, but in 17 John (1215-16) it again fell to the Crown, and was granted to Edmund Crouchback, Earl of Lancaster; and in Lonsdale we find that in 1126 Stephen, Earl of Bologne (before he became King), made over a large portion of the northern part to the monks of Furness, but the history of the early grantees of this district is not very clear. From these few chief lords were granted out various manors subject to rent, suit, and service, some portions in each district being retained in the King's possession. In the case of the transfer of the honour of Lancaster to Edmund Crouchback, it appears that the King had previously granted the custody of the county of Lancaster to Roger de Lancaster, to whom, therefore, letters patent were addressed, promising to indemnify him.[68]