ABSTRACT
Taxation had important implications for constitutional developments, because Parliament showed a willingness to criticize some of the policies which necessitated its being levied, and also on occasions asserted claims to supervise the way in which the revenues were employed. The main factor in the development of the customs system had been the financial demands of Edward III during the early stage of the Hundred Years War, when the parliamentary grant of the 'subsidy' on wool, in addition to earlier customs payments, had become the largest single element in the royal revenues. The administrative problems of conducting a reassessment probably lay behind the long survival of the fifteenth and tenth as the normal method of direct taxation, even although contemporaries appreciated that it had its weaknesses. On some occasions the King explicitly demanded a gift from his subjects, possibly on the grounds that it would be regarded as a substitute for personal service.
