German Coastal Fortifications in Denmark 1940-45 - Jens Andersen
The German fortification of Denmark underwent furious development during the five-year occupation, from 1940-45. This is true in terms of extent of constructions, as well as concepts employed, and the geography. The speed of the development is obvious when one looks at the number of coastal batteries: by the time the Germans completed their plans for the Danish coasts in the summer of 1940, they had emplaced fifteen batteries; by the time of their surrender there were eighty.

A strong fortification of the coasts of Denmark was not a goal in itself for the German Wehrmacht, who always tried to adjust the strength of the fortifications according to their assessment of the threat against the German control of Danish territory. The description of the development of the fortification, therefore, must be seen always in connection with the German grand strategy, the situation on the fronts and the threat estimate at any given time.