The site is dated to 580 but has Christian objects buried with the man. That seems quite early for one of the Saxon conquerors. Very interesting.
Christianity entered the former Roman province(s) of Britain multiple times, both during Roman times (from the Roman continent) and thereafter (mostly from Ireland). The Synod of Whitby (Northumbria; changed the observance of Easter from the Celtic church's method to the Vatican's) wasn't until 664, but by the time of Aethelstan's conquest of Devon/Cornwall in the 10th c, Christianiity had been around there for 700 years or so.