Though Henry's taxes were vexatious and never-ending, though his subservience to the pope and his flighty interference in foreign politics were ever irritating the magnates and the people, and though outbreaks of turbulence were not unknown during his long period of personal rule, it would yet be a mistake to regard the central years of the 13th century as an unprosperous period for England. Indeed it would be more correct to regard the period as one of steady national development in wealth, culture and unity. The towns were growing fast, and extending their municipal liberties; the necessities of John and the facile carelessness of Henry led to the grant of innumerable charters and privileges. As was to be seen again during the first period of the reign of Charles I., political irritation is not incompatible either with increasing material prosperity or with great intellectual development. The king's futile activity led to ever more frequent gatherings of the Great Council, in which the theory of the constitution was gradually hammered out by countless debates between the sovereign and his subjects. Every time that Henry confirmed the Great Charter, the fact that England was already a limited monarchy became more evident. It is curious to find that--like his father John--he himself contributed unconsciously to advances towards representative government. John's writ of 1213, bidding "discreet men" from each shire to present themselves at Oxford, found its parallel in another writ of 1253 which bids four knightly delegates from each county to appear along with the tenants-in-chief, for the purpose of discussing the king's needs. When county members begin to present themselves along with the barons at the national assembly, the conception of parliament is already reached. And indeed we may note that the precise word "parliament" first appears in the chroniclers and in official documents about the middle of Henry's reign. By its end the term is universally acknowledged and employed. Intellectual life. We may discern during these same years a great intellectual activity. This was the time of rapid development in the universities, where not only were the scholastic philosophy and systematic theology eagerly studied, but figures appear like that of the great Roger Bacon, a scientific researcher of the first rank, whose discoveries in optics and chemistry caused his contemporaries to suspect him of magical arts. His teaching at Oxford in 1250-1257 fell precisely into the years of the worst misgovernance of Henry III. It was the same with law, an essentially 13th-century study; it was just in this age that the conception of law as something not depending on the pleasure of the king, nor compiled from mere collected ancestral customs, but existing as a logical entity, became generally prevalent. The feeling is thoroughly well expressed by the partisan of Montfort who wrote in his jingling Latin verse:--