Further, I believe that as the 'barons' received their instructions from the sheriffs, so they also sent in their returns through those officers. The memorandum, for instance, on the missing _carta_ of Osbert fitz Hugh informs us that it was brought to the exchequer by William de Beauchamp. Now, William de Beauchamp was sheriff of the shire. This would account for the grouping of the returns 'per singulos comitatus', as Swereford expresses it, and indeed this arrangement would but follow the existing practice of collecting the scutage shire by shire. Returning now to the terms of the inquiry, it is obvious that the tenant (_baro_) to whom such queries were addressed must of necessity have belonged to one of these three classes-- (_a_) Those who had created _the exact number_ of knights' fees sufficient to discharge their 'service'. (_b_) Those who had created _more_ than sufficient. (_c_) Those who had created _less_ than sufficient. This last class requires some explanation. When the number of knights' fees created was not sufficient to discharge the baron's 'service', the balance of that service remained charged on the non-infeudated portion of his fief, that is, on the 'demesne', and was technically said to be 'super dominium'. It is all-important that this should be grasped, for it might otherwise be supposed that such a phrase as 'quot milites super dominium' implied the existence of actual knights enfeoffed on the demesne, which, to those who realize the working of the system of knight-service, is an absolute contradiction in terms. This, it will be found, beautifully explains the first article of the Assize of Arms (1181)--that every tenant is to keep in stock harness for as many knights 'quot habuerit feoda militum in dominio suo'.[50] That is to say, that if, after deducting the knights actually enfeoffed, there remained due from his fief a balance of knight-service, he must keep in readiness harness sufficient for those knights whom he would have to provide himself to discharge that balance.[51] Having made this point clear, I now pass to the immediate object of the inquest of 1166. What that object was, no one has as yet discovered. Dr Stubbs, for instance, in his preface to the Pipe-Roll of 1166, writes: 'On the immediate purpose for which the inquiry was made--and it can scarcely be doubted that it was for the collection of a scutage--we shall look for further information in the rolls of the succeeding years.' My own researches enable me to assert that this inquest formed part of a financial revolution hitherto ignored, which deserves to be compared with those other innovations in administration and finance that characterized the latter half of the twelfth century in England.