[hef19898]

A British claim to Calais even has some historical precedent, doesn't it?

[acjohnson55]

It was the last British territory in France, holding out until 1558.

https://tudorhistory.org/glossaries/c/calais.html

[Gupie]

There are the Channel Islands, but perhaps you could claim that the Channel Islands were the ones to occupy England and not vice versa since they were part of Normandy!