Mavis Batey (née Lever)

One of Bletchley Park's most effective codebreakers, Batey joined the team in May 1940 at just 19 years old, interrupting her German-language studies at University College London. Working under the eccentric cryptographer Dilly Knox, she helped crack the Italian Navy's Enigma variant. It was a plugboard-free machine that proved more tractable than German military versions.

In March 1941, Batey and her colleagues decrypted Italian naval signals that revealed a detailed plan to attack a Royal Navy convoy. The intelligence was forwarded directly to Admiral Cunningham, who used it to ambush the Italian fleet at the Battle of Cape Matapan, sinking three cruisers and two destroyers. Knox celebrated her contribution in verse: "When Cunningham won at Matapan, by the grace of God and Mavis." In December 1941, she broke an Abwehr Enigma message between Belgrade and Berlin that exposed the machine's internal wiring. This breakthrough eventually allowed British intelligence to confirm that Germany believed the disinformation being fed back through the Double-Cross System.

After the war, Batey built a distinguished second career as a garden historian. She served as secretary and later president of the Garden History Society, and published numerous books including Dilly: The Man Who Broke Enigmas (2009), a biography of Knox. She received the Veitch Memorial Medal in 1985 and was appointed MBE in 1987, both honors recognizing her work in garden conservation. She died on November 12, 2013, at age 92.