How did the Swiss let themselves get annexed?
Twenty years later
Dutch Calais? Why? Dutch Duinkerke/Dunkirk I can understand, they speak (in theory) still Dutch there, but I believe they don'ts speak Dutch in Calias since 800 AD.
Anyway I assume a POD at least after 1839 looking at the Dutch/Belgian borders. My guess is that the Netherlands sold Luxembourg to Prussia/ Germany which lead to a Franco-Prussian conflict in which Prussia beat France and annexed Elzasse-Lorraine and the Freche comte. The swiss supported France and got annexed too.
ASB that in 20 years, their have been no changes to the European borders outside the lowlands.
Germany invade after the French-Prussian war gave them the choose beetween becoming a adminstrated federal province (Like Alsace-Lorraine in OTL) or surrender and survive with all the Cantons as memberstates of Germany.