The question of Swereford's authority is one which it is absolutely necessary to deal with, because his statements have been freely accepted by successive historical writers, and have formed, indeed, the basis on which their conclusions rest. Now the presumption is naturally in favour of Swereford's knowledge of his subject. His introduction to the _Liber Rubeus_ is dated 1230, and he tells us that he had been at work among the records in the days of King John, under William of Ely[109] himself: he wrote with the actual rolls before him; he had been intimate with the leading officials of the exchequer, and enjoyed full knowledge of its practice and its traditions. I cannot wonder that, this being so, his positive assertions should have been readily believed, or that Mr Hall, when, for a short time, I was associated with him in preparing the Red Book for the press, should, with a kindly bias in favour of so venerable an authority, have shrunk from my drastic criticism of his famous introduction to that volume.
On the other hand we have Swereford's own admission that he worked from the rolls alone.[110] These rolls are, for all purposes, as accessible to us as they were to him, while we possess the advantage of having, in contemporary chronicles, sources of information which he did not use, and with which, indeed, he shows no sign of being even conversant. We must go, therefore, behind Swereford and examine for ourselves the materials from which he worked.
Passing, for the present, over minor points, I would fix on the 'Great Scutage', or 'Scutage of Toulouse', as the test by which Swereford's knowledge and accuracy must stand or fall. If he is in error on this matter, his error is so grievous and so far-reaching that it must throw the gravest doubt on all his similar assertions. The date of the expedition against Toulouse was June 1159 (the host having been summoned at Mid-Lent): from the chroniclers we learn that, to provide the means for it, and especially to pay an army of mercenaries, a great levy was made in England and beyond sea. The roll of the following Michaelmas records precisely such a levy, and the payments so recorded must have been made for the expenses of this campaign. But we can go further still; we can actually prove from internal evidence that sums accounted for on the roll of 1159 were levied expressly for the Toulouse campaign.[111] Yet we are confidently informed by Swereford that this levy was for a Welsh war, and that the scutage of Toulouse is represented by the levies which figure on the rolls of 1161 and 1162. He appears to have evolved out of his inner consciousness the rule that a scutage, though fixed and even paid in any given year, was never accounted for on the rolls till the year after.[112] But as even this rule will not apply to his calculation here, one can only suggest that he was absolutely ignorant of the date of the Toulouse campaign.[113] The value of Swereford's calculations is so seriously affected by this cardinal error, that one may reject with less hesitation his statement that the scutage of 1156 was taken for a Welsh war, and not, as there is evidence to imply, for a campaign against the king's brother. Swereford, again, may be pardoned for his ignorance of the fact that scutage existed under Henry I,[114] but when he unhesitatingly assigns the Domesday Survey to the fourteenth year of the Conqueror (1079-80), he shows us that the precision of his statements is no proof of their accuracy. On both these points he has misled subsequent writers.[115]