These three aids were carefully specified, and a reasonable rate was stipulated for, but not defined. In this respect the treatment here accorded to _aids_ is less satisfactory than that of _reliefs_ in chapter 2, which carefully defined the amount to be paid. It is probable that the framers of the present chapter relied on existing usage, which seems to have regarded the normal aid as one-fifth of the normal relief, _i.e._ as 20s. per knight’s fee. An alternative explanation is also possible, that the same “common counsel” which had the right to veto extraordinary aids, was also expected to determine the reasonable amount of the ordinary aids. ----- II. _Protection of Citizens of London from arbitrary Exactions._ Some attempt was made to protect the men of London, as well as the Crown tenants, from John’s demands for money. The insurgent leaders in this way discharged part of their debt to an ally with special claims upon their gratitude.[466] The Articles of the Barons had contained several important provisions affecting the capital; and these were embodied in the Charter in slightly altered terms, which suggest some influence at work not altogether friendly to the citizens.[467] The present clause of the completed charter, for example, uses only one word, “_aids_,” where the 32nd of the Articles of the Barons had referred to “tallages and aids.” There is no evidence to show whether the omission had been deliberately planned, or was merely the result of inadvertence; and the ambiguity inherent in both words makes it dangerous to hazard a dogmatic opinion on the practical effect of the alteration. Yet a clearly-marked line can be traced between the respective meanings of the two terms when they are technically used. ----- Footnote 466: See _supra_, p. 42. Footnote 467: See article 23 (which became c. 33), article 31 (c. 41), and article 32 (cc. 12 and 13), and cf. _supra_, pp. 140-1. Whether article 12 (c. 35) was more a benefit to, than a restraint upon, traders seems doubtful. ----- (1) “_Aid_” is the vaguer word, applicable to every payment which can be regarded as in any sense a free-will offering. It embraced gifts to the Crown, whether from prelate or burgess or feudal baron. London was stimulated towards acts of generosity by kings of England both before and after John. There were times when “voluntary” aids, like the “benevolences” of Tudor days, could not safely be withheld.