After the great storm of 1273. Winchelsea was no longer near the sea

@peterlee Henry VIII built quite a number of coastal defences. I don't know how far he went along the South coast but he protected Portlaand Roads, as it was called, by two gun batteries facing geach other across the sheltered bay. The ranges of the guns available was just enough to allow some overlap in the middle.

They survive, one structurally intact as Portland Castle. The other, Sandsfoot Castle, is a stabilised ruin whose gun-platform has long been lost to erosion of the cliff it stands on.

The Roads became protected as Portland Harbour by the late-19C building of huge breakwaters; and was a Royal Navy Base until the 1990s when it was closed and sold to become a commercial port..

The English Channel at that point is about 70 or so miles wide to the Cherbourg Peninsula and Normandy Beaches. Perhaps a bit wide for 16C North-bound invasions sailing across the prevailing wind, but not for the 20C D-Day and subsequent South-bound invasion!

@peterlee Something similar happened to Rye, by severe storms in the same era, and more gradual natural and man-made changes.

@ArishMell Winchelsea itself is Bastide Town like those in Aquitaine, built by Edward1, very similar to Monpazier.

Henry eighth tried to restore the harbour there, but miserably failed.

Now it is a favoured landing point for illegal immigrants across the channel.

@peterlee I've just been studying my AA Road Atlas, which at 4 miles to the inch does not show much detail, to understand that area better. The two towns are indeed quite a way inland.

I found too that The Royal Military Canal looping round from Rye basically cut off the Romney and Wallend Marshes from the rest of England but what strategic use it would have been against even more determined and even more illegal immigrants, is hard to see!