debitum_ to the crown, the king had no right to look beyond the 'baron', who was himself and alone responsible for the discharge of this service. It is, indeed, in this responsibility that lies the key to the situation. If the under-tenant of a knight's fee failed to discharge his service, it was not to him, but to his lord, that the crown betook itself. 'I know nothing of your tenant,' was in effect the king's position; 'you owe me, for the tenure of your fief, the service of so many knights, and that service must be performed, whether your under-tenants repudiate their obligations to yourself or not'. In other words the 'baron' discharged his service to the king, whereas the baron's under-tenants discharged theirs to their lord.[61] So the _Dialogus_ speaks of the under-tenant's 'numerum militum quos domino debuerat'. Let us then apply ourselves directly to the quotas of military service due from the 'barons' to the crown, and see if, when ascertained, they throw any fresh light on the real problem. No attempt, so far as I know, has ever been made to determine these quotas, and indeed it was the utter want of trustworthy information on the subject that led Swereford to undertake his researches in the thirteenth century. Those researches, unfortunately, leave us no wiser, partly from his defective method and want of the requisite accuracy; partly from the fact that what he sought was not abstract historical truth, but practical information bearing on the existing rights of the crown. We must turn therefore to the original authorities: (1) the _cartae baronum_, (2) the annual rolls. These were the two main sources of Swereford's information, as they must also be of ours. In the next part of this paper I shall deal with the evidence of the rolls, as checking and supplementing the _cartae baronum_. I shall analyse the church fiefs first, because we can ascertain, virtually with exactitude, the _servitium debitum_ of every prelate and of every head of a religious house who held by knight service. The importance of these figures, together with the fact that they have never, so far as I know, been set forth till now, has induced me to append them here in full detail. SEE SERVICE DUE SEE SERVICE DUE knights knights Canterbury 60 Bath 20 Winchester 60 London 20 Lincoln 60 Exeter 17-1/2[62] Worcester 50 [60] 'Chester' 15 Norwich 40 Hereford 15 Ely 40 Durham 10 Salisbury 32 Chichester 4 [2] York 20 [7]