It is impossible to resist the inference, from such evidence as we have, that the amount of the _servitium debitum_ was a matter of custom and tradition, and could not usually be determined by reference to written grants or charters. On this point the returns of three Essex tenants are most instructive, while their similarity is so striking, that, as in the case of the Shropshire _formulæ_, it can scarcely be due to accident. The Earl of Essex closes with the words: 'et homines mei dicunt mihi quod debeo Domino Regi lx. milites'. Walter fitz Robert, who follows him, writes: 'et hoc mihi homines mei intelligere faciunt, quod debeo inde Regi servitium de l. militibus'. William de Montfichet ends thus: 'et hoc faciunt homines mei mihi intelligere--quod pater meus deserviebat per xl. milites'. With these expressions we may compare those of William fitz Alan's tenants, who assert that his Norfolk fief 'non debet domino Regi nisi i. militem ... ut antiqui testantur'; that his Shropshire fief 'non debet Regi nisi x. milites in exercitu ... sicut antiqui testantur'; and that, as to his Wiltshire fief, 'non sumus certi quod servitium debeat Regi de hoc tenemento'. The Abbot of Chertsey, also, states his _servitium debitum_ with the proviso 'secundum quod scire possumus'. These expressions explain the uncertainty as to the _servitium debitum_ in such cases as the See of Worcester and Ramsey Abbey.[95] The same principle applies to the relation between the tenant-in-chief and his under-tenant. Thus the very first entry in the _cartae_ runs as follows: Willelmus de Wokindone iiij. milites et dimidium; et praeter hoc, ex testimonio curiae meae, dimidium exigo, quem ipse se non debere defendit. Of another tenant on the same fief we read: 'praeter hoc, _ex testimonio curiae meae_, adhuc j. militem exigo'. Here, we see, appeal is made not to record evidence, but to oral testimony. So, too, the Bishop of Exeter adds this clause to his return: Et praeter hos omnes, sicut _a multis audivi_, comes Gloucestriæ, et comes Hugo, et comes de Clare debent tenere de Exoniensi Episcopo; sed nullum ei servitium faciunt vel recognoscunt. Surely in all such cases as these the obvious inference is that the tenant had been enfeoffed _sine carta_, or in the very words of the Provisions of the Barons (1259) 'feofatus sine carta a tempore conquestus vel alio antiquo feofamento' (§ 1).