Jane Fawcett MBE (née Janet Carolin (or Caroline) Hughes), 4 March 1921 – 21 May 2016) was a British codebreaker, opera singer, and heritage preservationist. She recently became known for her role in decoding a message, which led to the sinking of the German battleship Bismarck.
In 1963 Fawcett took an executive position with the Victorian Society, founded in 1957 as a heritage preservation organisation dedicated to preserving Victorian architecture and works. As its secretary, she was effectively the chief executive, working closely with the director, Sir Nikolaus Pevsner, to save many buildings from demolition. She was referred to as "the furious Mrs. Fawcett" by BR executives for her role in fighting to preserve historic railway stations, and was instrumental in the preservation of St. Pancras Railway Station and its gothic Midland Grand Hotel. She also worked to save much of Whitehall from destruction.[9]
In later years she taught preservation at the Architectural Association School of Architecture.
The above information is condensed from the Wikipedia entry.