In 680 AD, the landscape of the "Manhood Peninsula" (where Bognor and Selsey sit) looked very different from the coastline we see today. Coastal erosion has been so aggressive here that it's estimated the shoreline has retreated by at least one to two miles since the Saxon era.

The "Island" of Selsey

In the 7th century, Selsey was essentially an island or a "near-island."

• The Inlet: A wide tidal inlet or channel likely separated Selsey from the mainland, running from what is now Pagham Harbour through to Bracklesham Bay.

• Bucgan ora (Bognor): This wasn't just a beach; it was a "landing place" on the edge of a large, swampy estuary. Historians believe the area between Bognor and Selsey was a series of lagoons and salt marshes.

The Submerged Landmarks

One of the most fascinating aspects of this geography is what has been lost to the sea:

• The Cathedral Site: The original Selsey Abbey/Cathedral (founded by Wilfrid) is widely believed to be underwater. While some suggest it was at Church Norton, local legend and some geological surveys point to a site now about a mile out at sea, in an area still called "The Park" (once a literal deer park belonging to the Bishops).

• The Mixon Rocks: This reef, now visible only at low tide and located about a mile off Selsey Bill, was likely dry land and part of the Roman and early Saxon settlement. Some historians think the original Cymenes ora (where the Saxons first landed in 477 AD) might have been near these rocks.