KNIGHT-SERVICE, the dominant and distinctive tenure of land under the feudal system. Its origin may be traced to the mailed horseman, armed with lance and sword, who became the most important factor in battle. This novel system was introduced after the Conquest by the Normans, who relied essentially on their mounted knights, while the English fought on foot. They were already familiar with the principle of knight-service, the knight's fee, as it came to be termed in England, being represented in Nor mandy by the fief du haubert, so termed from the hauberk or coat of mail (lorica) which was worn by the knight. The coronation charter of Henry I. (I ioo) speaks of those holding by knight service as milites qui per loricam terras seas deserviunt.
The Conqueror divided the lay lands of England among his followers, to be held by the service of a fixed number of knights in his host, and imposed the same service on most of the great eccle siastical bodies. No record evidence exists of this action on his part, and the quota of knight-service exacted was not determined by the area or value of the lands granted, but was based upon the unit of the feudal host, the constabularia of ten knights. Of the tenants in-chief or barons (i.e., those who held directly of the Crown), the chief ones were called on to find one or more of such units, while of the lesser ones some were called on for five knights, i.e., half a constabularia. The same system was adopted in Ireland when that country was conquered under Henry II. The baron who had been enfeoffed by his sovereign on these terms could provide the knights required either by hiring them for pay or, more con veniently when wealth was mainly represented by land, by a proc ess of subenfeoffment, analogous to that by which he himself had been enfeoffed.
The primary obligation incumbent on every knight was service in the field, when called upon, for 4o days a year, with specified armour and arms. There was, however, a standing dispute as to whether he could be called upon to perform this service outside the realm, nor was the question of his expenses free from difficulty.
In addition to this primary duty he had, in numerous cases at least, to perform that of "castle ward" at his lord's chief castle for a fixed number of days in the year. On certain baronies also was incumbent the duty of providing knights for the guard of royal castles, such as Windsor, Rockingham and Dover. Under the feu dal system the tenant by knight-service had also the same pecuni ary obligations to his lord as had his lord to the king. These con sisted of (I) "relief," which he paid on succeeding to his lands; ( 2 ) "wardship," i.e., the profits from his lands during a minority; (3) "marriage," i.e., the right of giving in marriage, unless bought off, his heiress, his heir (if a minor) and his widow; and also of the three "aids" (q.v.). The chief sources of information for the extent and development of knight-service are the returns (cartae) of the barons (i.e., the tenants-in-chief) in 1166, informing the king, at his request, of the names of their tenants by knight service with the number of fees they held, supplemented by the payments for "scutage" (q.v.) recorded on the pipe-rolls, by the later returns printed in the Testa de Nevill, and by the still later ones collected in Feudal Aids. In the returns made in 1166 some of the barons appear as having enfeoffed more and some less than the number of knights they had to find. In the latter case they described the balance as being chargeable on their "demesne," i.e., on the portion of their fief which remained in their own hands. These returns further prove that lands had already been granted for the service of a fraction of a knight, such service being in practice already commuted for a proportionate money payment ; and they show that the total number of knights with which land held by military service was charged was not, as was formerly supposed, 6o,000, but probably somewhere between 5,00o and 6,000. Similar returns were made for Normandy, and are valuable for the light they throw on its system of knight-service.