The first visitation under the assize was at once begun by Richard de Lucy and Geoffrey de Mandeville, earl of Essex;[594] and the Pipe Roll of the year furnishes some indications of its immediate results. The sums credited to the treasury for the pleas of the Crown reach a far greater amount than in the earlier rolls, and its receipts are further swelled by the goods and chattels of criminals condemned under the assize,[595] which were explicitly declared forfeit to the king.[596] The clause binding all qualified persons to be ready to serve on the juries was strictly enforced; one attempt to evade it was punished with a fine of five marks.[597] Another clause, enjoining upon the sheriffs the construction and repair of gaols for the detention of criminals, was carried into effect with equal vigour.[598] The work of the two justiciars was apparently not completed till the summer of 1167.[599] In that year pleas of the forest were held throughout the country by Alan de Neville; and in 1168 seven barons of the Exchequer made a general visitation of the shires for the collection of an aid on the marriage of the king’s eldest daughter.[600] This last was primarily a fiscal journey; the aid itself was a strictly feudal impost, assessed at one mark on every knight’s fee.[601] It was however levied in a remarkable manner. The Domesday survey, which by a few modifications in practice had been made to serve as the rate-book of the whole kingdom for eighty years, was at last found inadequate for the present purpose. A royal writ was therefore addressed to all the tenants-in-chief, requiring from them an account of the knights’ fees which they held and the services due upon them, whether under the “old infeoffment” of the time of Henry I., or under the “new infeoffment” since the resettlement of the country by his grandson.[602] The answers were enrolled in what is known as the _Black Book of the Exchequer_[603] and the aid was levied in accordance with their contents. The whole process occupied a considerable time; the preparations seem to have begun shortly after Matilda’s betrothal, for we hear of the purchase of “a hutch for keeping the barons’ letters concerning their knights” as early as 1166,[604] yet the collection of the money was not finished till the summer of 1169,[605] a year and a half after her marriage. The labours of the barons employed in it were however not confined to this one end; as usual, their travels were turned to account for judicial purposes,[606] and the system begun by the assize of Clarendon was by no means suffered to fall into disuse. [594] Stubbs, _Constit. Hist._, vol. i. p. 470. _Gesta Hen._, vol. ii., pref. pp. lxiv, lxv. [595] See Stubbs, _Constit. Hist._, vol. i. p. 471. [596] Ass. Clar., c. 5 (Stubbs, _Select Charters_, pp. 143, 144).