It was far otherwise with the duties of military service, which were rendered every year more unwillingly, partly because of the increased frequency of warlike expeditions, partly because of the greater cost of campaigning in distant lands like Poitou, partly because the English barons were completely out of sympathy with John’s foreign policy and with him. We have seen that the want of definition and looseness of practice in the reign of William the Conqueror left to future ages a legacy fertile in disputes. William I. and his barons lived in the present; and the present did not urgently call for definition. Therefore, the exact duration of the military service to be rendered, and the exact conditions (if any) on which exemption could be claimed, were left originally quite vague. Such carelessness is easily explained. Both Crown and barons hoped that by leaving matters undefined, they would be able to alter them to their own advantage. This policy was sure to lead to bitter quarrels in the future, but circumstances delayed their outbreak. The magnates at first readily followed William to the field wherever he went, since their interests were identical with his, while warfare was their normal occupation. The exact amount of military service was gradually fixed by custom, and both sides acquiesced in reckoning the return due (_servitium debitum_) for each knight’s fee or _scutum_ as the service of one fully armed horseman during forty days. There were still, however, innumerable minor points on which disputes might arise, and these remained even in 1215. Indeed, although several chapters of the Great Charter attempted to settle certain of these disputed points, others were left as bones of contention to subsequent reigns: for example, the exact equipment of a knight; the liability to serve for more than forty days on receiving pay for the extra time; what extent of exemption (if any) might be claimed by churchmen holding baronies on the ground that they could not fight in person; how far a tenant might compromise for actual service by tendering money; whether attendance and money might not both be refused, if the King did not lead his forces in person; and whether service was equally due from all estates for foreign wars as for home ones.[118] ----- Footnote 118: Some of these questions might be answered in particular cases by the terms of special charters. Thus the _Hundred Rolls_ (1279) relate how Hugh de Plesens held the Manor of Hedington, and was liable for one knight’s fee when scutage ran; that he must go with the King and serve him for forty days at his own expense, and thereafter at the expense of the King. _Rot. Hund._, II. p. 710; cf. for _France, Etablissements de St. Louis_, I. c. 65.