In the seventh century the pagan Anglo-Saxons were converted to Christianity () mainly by missionaries sent from Rome. Irish missionaries from Iona, who were proponents of Celtic Christianity, were influential in the conversion of Northumbria, but after the Synod of Whitby in 664, the Anglo-Saxon church gave its allegiance to the Pope. Background Christianity was present in Roman Britain from at least the third century, introduced by tradesmen, immigrants and legionaries, although most of the latter probably followed Mithraism. Diocletian's edicts of persecution, of 303 were not rigorously enforced by Constantius Chlorus. In 313, his son, Constantine, issued the "Edict of Milan" allowing the practice of Christianity in the Empire. The following year three bishops from Britain attended the Council of Arles. They were Eborius from the city of Eboracum (York); Restitutus from the city of Londinium (London); and Adelfius, the location of whose see is uncertain. The presence of these three bishops indicates that by the early fourth century, the British Christian community was already both organised on a regional basis, and had a distinct episcopal hierarchy. Around 429, the bishops of Britain requested assistance from their colleagues in Gaul in dealing with Pelagianism. Germanus of Auxerre and Lupus, Bishop of Troyes were sent. During his sojourn in Britain, Germanus, a former government official, is reported to have led the native Britons to a victory against Pictish and Saxon raiders. In 396, Victricius of Rouen was asked to go to Britain to resolve some doctrinal matters. In his De Laude Sanctorum (On the Praise of the Saints), he describes Britain as a wild and hostile place dealing with heresy and paganism. The Anglo-Saxons were a mix of invaders, migrants and acculturated indigenous people. Before the withdrawal of the Romans, Germanic militia had been brought into Britain who had been stationed there as foederati. The migration continued with the departure of the Roman army, when Anglo-Saxons were recruited to defend Britain; and also during the period of the Anglo-Saxon first rebellion of 442. They settled in small groups covering a handful of widely dispersed local communities, and brought from their homelands the traditions of their ancestors. There are references in Anglo-Saxon poetry, including Beowulf, that show some interaction between pagan and Christian practices and values. There is enough evidence from Gildas and elsewhere that it is safe to assume some continuing form of Christianity survived. The Anglo-Saxons took control of