It has been well described by Pollock and Maitland (I. 294) as “the great residuary tenure.” In Scotland the “residuary tenure” is not socage but “feu” (resembling the English fee-farm). Holdings in feu are still familiar to Scots lawyers. They are originated by a formal charter, followed by registration (the modern equivalent of infeftment or feudal investiture), thus preserving an unbroken connection with the feudal conveyancing of the Middle Ages. The interest of historians naturally centres round tenure by knight’s service, which is the very kernel of the feudal system. Lack of definition in the middle ages was a fruitful source of quarrel. For a century and more after the Norman Conquest, the exact amount and nature of the military services due by a tenant to his lord were left vague and undetermined. The early Norman Kings had gradually superseded the old Anglo-Saxon Crown tenants by new ones of Norman or French extraction, without formulating any code of regulations for the future. The whole of England had thus been carved into a number of estates—the larger known as honours or baronies, and the smaller as manors. Each Crown tenant (with two exceptions, of which the Conqueror’s favourite foundation of Battle Abbey was one) held his lands on condition of furnishing a certain number of fully armed and mounted soldiers, always ready to obey the King’s summons in the event of war. High authorities differ as to when and by whom the amount of each vassal’s service was fixed. The common view (promulgated by Prof. Freeman[81] with his usual vehemence), attributes the allocation of specific service to Ranulf Flambard, the unscrupulous tool of William Rufus. Mr. J. H. Round[82] has recently urged convincing reasons in support of the older view which attributes it to William I. Two facts, apparently, are certain: that within half a century from the Conquest each military tenant was burdened with a definite amount of knight’s service; and, further, that no formal record of the amount of such service was made at the time. There were, as yet, no written charters, and thus the possibility of disputes remained. Probably such grants would be made in full _Curia_, and the only record of the conditions would lie in the memory of the Court itself. ----- Footnote 81: _Norman Conquest_, V. 377; _Hist. of William Rufus_, 335–7. Footnote 82: _Feudal England_, p. 228 _et seq._ Long before the date of Magna Carta, the various obligations had been grouped into three classes, which may be arranged according to their relative importance, as _services_, _incidents_, and _aids_. Under each of these three heads, disputes continually arose between the lord who exacted and the vassal who rendered them.[83] ----- Footnote 83: