Two letters of Gregory the Great, written at the time of the mission of St. Augustine, are a key to the methods adopted by the apostles of the West. In June 601, writing to Ethelbert of Kent by the hands of abbot Mellitus, Gregory bade the new convert show zeal in suppressing the worship of idols, and throwing down their fanes[342]. Having written thus, the pope changed his mind. Before Mellitus could reach England, he received a letter instructing him to expound to Augustine a new policy. ‘Do not, after all,’ wrote Gregory, ‘pull down the fanes. Destroy the idols; purify the buildings with holy water; set relics there; and let them become temples of the true God. So the people will have no need to change their places of concourse, and where of old they were wont to sacrifice cattle to demons, thither let them continue to resort on the day of the saint to whom the church is dedicated, and slay their beasts no longer as a sacrifice, but for a social meal in honour of Him whom they now worship[343].’ There can be little doubt that the conversion of England proceeded in the main on the lines thus laid down by Gregory. Tradition has it that the church of Saint Pancras outside the walls of Canterbury stands on the site of a fane at which Ethelbert himself once worshipped[344]; and that in London St. Paul’s replaced a temple and grove of Diana, by whom the equivalent Teutonic wood-goddess, Freyja, is doubtless intended[345]. Gregory’s directions were, perhaps, not always carried out quite so literally as this. When, for instance, the priest Coifi, on horseback and sword in hand, led the onslaught against the gods of Northumbria, he bade his followers set fire to the fane and to all the hedges that girt it round[346]. On the other hand, Reduald, king of East Anglia, must have kept his fane standing, and indeed he carried the policy of amalgamation further than its author intended, for he wavered faint-heartedly between the old religion and the new, and maintained in one building an _altare_ for Christian worship and an _arula_ for sacrifice to demons[347]. Speaking generally, it would seem to have been the endeavour of the Christian missionaries to effect the change of creed with as little dislocation of popular sentiment as possible. If they could extirpate the essentials, or what they considered as the essentials, of heathenism, they were willing enough to leave the accidentals to be worn away by the slow process of time. They did not, probably, quite realize how long it would take. And what happened in England, happened also, no doubt, on the continent, save perhaps in such districts as Saxony, where Christianity was introduced _vi et armis_, and therefore in a more wholesale, if not in the end a more effectual fashion[348].