The problem for William and his companions was how to organize this military superiority as a means of orderly government, and this problem wore a twofold aspect. William had to control his barons, and his barons had to control their vassals. Their methods have been summed up in the phrase, the "feudal system," which William is still popularly supposed to have introduced into England. On the other hand, it has been humourously suggested that the feudal system was really introduced into England by Sir Henry Spelman, a seventeenth-century scholar. Others have maintained that, so far from feudalism being introduced from Normandy into England, it would be truer to say that feudalism was introduced from England into Normandy, and thence spread throughout France. These speculations serve, at any rate, to show that feudalism was a very vague and elusive system, consisting of generalizations from a vast number of conflicting data. Spelman was the first to attempt to reduce these data to a system, and his successors tended to forget more and more the exceptions to his rules. It is now clear that much that we call feudal existed in England before the Norman Conquest; that much of it was not developed until after the Norman period; and that at no time did feudalism exist as a completely rounded and logical system outside historical and legal text-books. The political and social arrangements summed up in the phrase related primarily to the land and the conditions of service upon which it was held. Commerce and manufactures, and the organization of towns which grew out of them, were always exceptions to the feudal system; the monarchy saved itself, its sheriffs, and the shires to some extent from feudal influence; and soon it set to work to redeem the administration of justice from its clutches. In all parts of the country, moreover, there was land, the tenure of which was never feudalized. Generally, however, the theory was applied that all land was held directly or indirectly from the king, who was the sole owner of it, that there was no land without a lord, and that from every acre of land some sort of service was due to some one or other. A great deal of it was held by military service; the tenant-in-chief of this land, who might be either a layman or an ecclesiastic, had to render this military service to the king, while the sub-tenants had to render it to the tenants-in-chief. When the tenant died his land reverted to the lord, who only granted it to the heir after the payment of a year's revenue, and on condition of the same service being rendered. If the heir were a minor, and thus incapable of rendering military service, the land was retained by the lord until the heir came of age; heiresses could only marry with the lord's leave some one who could perform his services. The tenant had further to attend the lord's court--whether the lord was his king or not--submit to his jurisdiction, and pay aids to the lord whenever he