The libraries of the religious houses, and in particular those of the great and ancient houses of the black monks, were throughout the Middle Ages by far the most considerable repositories of books in the country. Only two other classes of library existed: those attached to a cathedral, and those belonging to an academic college or to the university itself. Neither of these could rival the great monastic libraries of England. No English cathedral at any time, with the possible exception of Canterbury, could show a collection of ancient books at all comparable with those of the cathedrals of northern Italy or southern Germany which could trace an unbroken existence back to Lombardic or Merovingian times. Moreover, during the centuries from the Conquest onwards ten of the seventeen English cathedrals, including several of the most important, had regular chapters; their libraries therefore were monastic. Of the rest, only Exeter could boast a respectable nucleus of ancient books coming down from before the Conquest, and all secular cathedrals lacked the corporate wealth and jealous care of an undying community. As for the academic libraries, they were of late origin and less catholic in their choice of books, and though by the end of the fifteenth century the aggregate wealth of books at Oxford and Cambridge was great, and in late scholastic and early humanistic literature surpassed any single monastic library, the greater abbeys and cathedral priories possessed to the end the largest collections of books of all dates and classes.