Heligoland

In 1956 sea area Heligoland became German Bight. But why did the North Sea island, which for nearly a century had demonstrated its loyalty to Britain, lose its identity? How had this once peaceful haven become, as Admiral Jacky Fisher exclaimed 'a dagger pointed at England's heart'? Behind the renaming of Heligoland lies a catalogue of deceit, political ambition, blunder and daring....