At first she was employed by the London Section to check the personal columns of The Times for coded spy messages. Then, in 1940, she was recruited to work as a codebreaker at Bletchley Park. She worked as an assistant to Dilly Knox, and was closely involved in the decryption effort before the Battle of Matapan. According to The Daily Telegraph, she became so familiar with the styles of individual enemy operators that she could determine that two of them had a girlfriend called Rosa. Batey had developed a successful technique that could be used elsewhere. Although Mavis was just 19, she started working on the Italian Naval Enigma machine, and by late March 1941 she effectively broke into their framework, deciphering a message which said "Today's the day minus three". She and her colleagues worked for three days and nights and discovered that the Italians were intending to assault a Royal Navy convoy transporting supplies from Cairo, Egypt to Greece. The messages they deciphered provided a detailed plan of the Italian assault. In December 1941 she broke a message between Belgrade and Berlin that enabled Knox's team to work out the wiring of the Abwehr Enigma, an Enigma machine previously thought to be unbreakable. Later, Batey broke another Abwehr machine, the GGG. This enabled the British to be able to read the Abwehr messages and confirm that the Germans believed the Double-Cross intelligence they were being fed by the double agents who were recruited by Britain as spies. While at Bletchley Park she met Keith Batey, a mathematician and fellow codebreaker whom she married in 1942.
Publications
Mavis Batey wrote a biography of Dilly Knox: ‘Dilly: The Man Who Broke Enigmas’. The book gives a summary of the government codes and cypher school's codebreaking operation in Bletchley Park. It also describes her code breaking of the Italian Enigma which contributed to the British Navy's success at the Battle of Cape Matapan.
Later life and awards
Batey spent some time after 1945 in the Diplomatic Service, and then brought up three children: two daughters and a son. She published a number of books on garden history, as well as some relating to Bletchley Park, and served as President of the Garden History Society, of which she became Secretary in 1971. She was awarded the Veitch Memorial Medal in 1985, and made a Member of the Order of the British Empire in 1987, in both cases for her work on the conservation of gardens. Batey, aged 92 and a widow since 2010, died on 12 November 2013. In 2005, The Gardens Trust held the first Annual Mavis Batey Essay Prize, a competition geared towards international students who are enrolled in a university, institution of higher education or who have recently graduated from one. The award celebrates Batey's achievements and advocacy in gardening. 2020 will be the sixteenth time that the competition is held.
