When the Columban Church had existed in Northumbria for about thirty years, new influences arose, before which that monastic form gradually declined. The principal of these influences came from the South, and was part of that steady pressure from Rome which by degrees brought all Churches into uniformity of doctrine and observance. England was to a great extent the spiritual child of Rome, having been reconverted to the faith by the direct intervention of the Pope after the desolation caused by the heathen Danes. This was accomplished by the mission of St. Augustine, who was sent by Pope Gregory to England in 596 for the reformation of religion. The ecclesiastics from Rome brought with them the Roman forms and observances and the Roman mode of building. Thus St. Augustine, so soon as he was established in Kent, set about the erection, at Canterbury, of a cathedral, with two towers attached to the nave and a circular baptistry, in imitation of St. Peter’s at Rome. Other instances occur of the introduction of building with stone after the Roman manner. Bede describes how Benedict Biscop, in 676, brought masons from Gaul to carry out buildings in stone, and how the churches of St. Peter at Monkwearmouth, and St. Paul at Jarrow, were erected by Benedict Biscop (670-80) with stone, “according to the manner of the Romans.” Bede further mentions that Nectan, King of the Northern Picts, sought, in 710, for masons to be sent to him from Monkwearmouth, who should build churches for him according to the fashion of the Romans. St. Winifred, Bishop of York, the great opponent of the Columbans in Northumbria, had also erected stone churches in the seventh century after the Roman manner at Hexham, York, and Ripon. Northumbria was at this period (during the seventh and part of the eighth centuries) the most powerful and advanced portion of England. It was the nursery of learning and poetry, the home of Bede and Caedmon. Religion also flourished, as is proved by the remains of the pre-Conquest churches which still survive.[29] Many of these show traces of the works of the ancient Romans in the country, being built, partly at least, with Roman wrought stones from the ruins in the district. The influence of the Columban period is observable in the numerous crosses carved with Celtic work which still survive in Northumbria.