A matter of twenty years later, in the reign of Constantine, the church was rebuilt, and completed by 337. What the shape of the first one was can only be conjectured. It would most probably be based upon the temple. The second was undoubtedly Romanesque, if we can rely upon the dates of its rebuilding. They fall conveniently between 306 and 337, a period of marvellous development of ecclesiastical architecture based upon classical remains, which the favourable attitude of Constantine towards Christianity encouraged. Converts in Rome had increased to such numbers that it was felt that some covered-in space was essential to protect the congregation against the sun's hot rays and inclement weather, the more especially as such a building, far from attracting hostile attention, would serve to the furtherance of Christianity. The form it took was the conversion of the basilica. As anything that came from Rome was looked upon as a correct thing to copy, it is not surprising to learn that travelling merchants and missionaries were able to control the taste of the cities they passed through. In this way each country adopted the basilica, though in many features they differed from each other, consequent on customs, surroundings, and climatic conditions. However, about the year 597, the pagan Saxons appear to have destroyed the church. We come then to the first church of St. Paul's of which we have authentic record. It was built by Ethelbert, King of Kent, in 607. He had first to obtain the sanction of Sebert, who claimed London as being in his dominion of the East Angles. To this see Mellitus was appointed as the first bishop. He was one of the forty monks who had accompanied Augustine in 597 to help to carry out Pope Gregory the Great's scheme, which was to divide England into two provinces with metropolitans of equal dignity at London and York, with twelve suffragans to each. Since then London's see has become third, ranking next to York. In the course of four hundred and eighty years, 607-1087, no doubt Ethelbert's church underwent considerable alteration, probably commencing with a very humble building, perhaps chiefly of wood, and as portions got out of repair such characteristics of stone buildings, as learnt from travellers returning from Italy, were introduced, thus gradually transforming the Saxon church to architecture "in the Roman way." For after the departure of the Romans the Britons at first appear to have returned to primitive methods of architecture. It is only as time progressed that they gradually became initiated, through the visits of travellers, into the working of stone, which, after the arrival of the Normans, came into more general practice.