No, the real story of Dunwich is much more exciting than the fantasy. To start with, we need to recognise how much the Suffolk coast has changed in the last 2000 years. The Dunwich area has changed no more than anywhere else. Further south, a large number of villages and their churches have been lost to the sea, and to stand in Aldeburgh is to see a town cut in half. North of Dunwich, the sea has carried off most of Pakefield in the last century, but further north than that, the old centre of Lowestoft is now further away from the sea than it was 500 years ago.
Tides are funny things.
The ruins of All Saints, in a postcard of 1904. The Romans knew Dunwich, but it first comes to prominence as Dumnoc, the see of the Bishop who would become St Felix. Miles Jebb, in his book Suffolk , describes Dunwich as the 'ignition point of English Catholicism'. It was from here that the missionaries set out across the land of the Angles, working very much against the grain until St Augustine arrived, and turned them into the establishment. The real Bishops of Dunwich didn't hang around for long.