Fortress Europe

Fortress Europe is a Battle honour accorded to Royal Air Force and allied squadrons during the Second World War, but to qualify, operations had to be made by aircraft based in the British Isles against targets in Germany, Italy and enemy-occupied Europe, in the period from the fall of France to the Normandy invasion. Concurrently the term was being used in Germany with a very different sense which grew to have a broader usage from the German "Festung Europa (Fortress Europe)"— a term used by Hitler and his staff to refer to the Atlantic wall and other planning the German nation set in place to stymie any invasion attempt by the allied armies during the same war. The term was subsequently used by corespondents and historians in the English language.

Thus it also refers to the Axis attempts to fortify the whole of occupied Europe, including the building of the Atlantic Wall to prevent invasion from the British Isles.

Currently, it is the term given (usually pejoratively) to the concept of the European Union efforts to make it difficult for illegal immigrants to enter the Union.