Within that century the kingdoms of the Heptarchy successively became Christian, and those among them which had relapsed returned to the Faith. Sovereigns, many of whom had boasted a descent from Odin himself, stood as interpreters beside the missionaries when they preached, and rivalled each other in the zeal with which they built churches, some of which were founded on the sites of ancient temples, though, in other cases, with a charitable prudence, the existing fanes were spared, purified, and adapted to Christian worship. At Canterbury and York, cathedrals rose, and on many a site besides; and when the earlier had been destroyed by fire, or had fallen through decay, fabrics on a vaster scale rose above their ruins, and maintained a succession which lasts to this day. Monasteries unnumbered lifted their towers above the forests of a land in which the streams still ran unstained and the air of which had not yet been dimmed by smoke, imparting a dignity to fen and flat morass. Round them ere long cities gathered, as at St. Albans, Malmesbury, Sherborne, and Wimborne; the most memorable of those monasteries being that at Canterbury, and that at Westminister, dedicated to St. Peter, as the cathedral church near it had been dedicated to St. Paul. In the North they were at least as numerous. The University of Oxford is also associated with that early age. It was beside the Isis that St. Frideswida raised her convent, occupied at a later date by canons regular, and ultimately transformed into Christ Church by Cardinal Wolsey--becoming thus the chief, as it had been the earliest, among the schools in that great seat of learning which within our own days has exercised a religious influence over England not less remarkable than that which belonged to its most palmy preceding period. During that century England produced most of those saintly kings and queens whose names still enrich the calendar of the Anglo-Saxon Church, sovereigns who ruled their kingdoms with justice, lived in mortification, went on pilgrimages, died in cloisters. The great missionary work had also begun. Within a century from the death of St. Augustine, apostles from England had converted multitudes in Germany, and St. Wilfrid had preached to the inhabitants of Friesland. Something, moreover, had been done to retrieve the past. The Saxon kings made amends for the wrongs inflicted by their ancestors upon the British Celts, endowing with English lands the churches and convents founded by them in Brittany. King Kenwalk of Wessex showed thus also a royal munificence to the Celtic monastery of Glastonbury, only stipulating in return that the British monks there, condoning past injuries, should offer a prayer for him when they knelt at the tomb of King Arthur.