Christianity seems to have survived in Dumnonia after the Roman departure from Britain, with a number of late Roman Christian cemeteries extending into the post-Roman period. In the 5th and 6th centuries the area was allegedly evangelised by the children of Brychan and saints from Ireland, like Saint Piran; and Wales, like Saint Petroc or Saint Keyne. There were important monasteries at Bodmin and Glastonbury; and also Exeter where 5th century burials discovered near the cathedral probably represent the cemetery of the foundation attended by Saint Boniface (although whether this was Saxon or Brythonic is somewhat controversial). Sporadically, Cornish bishops are named in various records until they submitted to the See of Canterbury in the mid-9th century. Parish organisation was a later development of fully Normanised times.