Mavis Batey

Mavis Batey was 19 when she joined Bletchley Park with no formal training in cryptography. She broke the Italian Navy's Enigma cipher, revealing the fleet's position before the Battle of Cape Matapan in March 1941. Later she broke the German Abwehr's Enigma traffic -- a different variant than Turing's Naval Enigma -- which identified the Eppler spy ring in Cairo and contributed to the Double-Cross system that turned German spies into British double agents. Her work directly supported deception operations that misled Hitler before Normandy.