Blagg: Role worth remembering
Mavis Batey died the other day. Most people have never heard of her, but she played a key role in the secret code breaking by Great Britain during World War II.
She worked at Bletchley Park, a rundown mansion surrounded by hastily thrown up huts which housed dozens of hard-working cryptoanalysts and mathematicians sworn to secrecy. They worked 24 hours a day, seven days a week trying to decode German and Italian messages.
They succeeded, for the most part, and in doing so changed the conduct of the war. Their modern successor in this country is the National Security Agency, whose super computers sift through millions of emails, phone calls and other messages every day.
The idea of using computers to decode messages was invented at Bletchley Park.
Batey was a college student studying German before she became one of Bletchley Park’s best decoders. She decrypted a message that led to a stunning British victory over the Italian navy in the Mediterranean and also cracked the secret messages of the Abwehr, the German intelligence service, a breakthrough that helped ensure the success of the D-day landings.
“She was the last of the great break-in experts ... who broke codes or ciphers that no one else had ever broken,” said British historian Michael Smith, who wrote several books on Bletchley Park. “She was a remarkable woman and someone I will never forget, nor will anyone who ever met her.”
The greatest challenge faced by the British codebreakers was a German coding machine called Enigma. It was basically an analog computer that used rotating wheels to scramble messages and then to unscramble them at the receiving end after they’d been transmitted by radio.
One day, Batey was examining a message coded on an Italian navy Enigma and noticed there was not one L in it. Knowing that the machine never encoded a letter as itself, she suspected that she was looking at a test message a lazy operator had made by repeatedly pressing the L key.
That insight allowed her to reconstruct the settings of the main Italian naval Enigma. Then, in March of 1941, she was able to decode an important dispatch: “Today’s the day minus three.” The next intercepted message supplied details of the battle plan, including the number of Italian warships and the time and location of the assault.
“Why they had to say that I can’t imagine,” Batey said later. “It seems rather daft, but they did.” The information allowed the Royal Navy to hand Italy its worst defeat at sea: In the Battle of Cape Matapan, off the Greek coast, more than 2,000 Italian sailors died and five Italian ships were destroyed.
Batey and the others at Bletchley Park kept the Allied High Command informed of the inner workings of the Axis for several years, but there were limits to what they could learn. One famous failure happened during the German bombing campaign against British cities.
It’s often cited as an example of a cold-blooded decision to sacrifice human lives for long-term advantage, but that interpretation is wrong.
A series of Enigma messages to German bomber forces made it clear that several major raids were being planned on specific cities. But the Germans used code names for the actual targets, even though the whole message was encrypted on Luftwaffe Enigma machines.
Ones of the cities was called “Corn” in the bombing orders — but nobody knew what that referred to. It turned out that Corn was Coventry.
Hundreds of Britons died in the Coventry raid.
After the war, some historians have maintained that Winston Churchill knew the raid was aimed at Coventry, but refused to strengthen its defenses because he was afraid that would tip off the Germans that Bletchley had broken its code.
That’s simply not true. Those who were in Churchill’s inner circle of advisers say that the best guess for “Corn” was London, and that upon hearing that, the pugnacious Prime Minister promptly changed his plan to spend the night at his home in the country and returned to London — insistent on being at the center of what he thought was the target.
It wasn’t until they heard of the enormous damage to Coventry that British planners realized that they had guessed wrong.
After the war, Batey became one of England’s best-known garden historians and a leading preservationist. She also was a model for the code-breaker played by actress Kate Winslet in “Enigma,” the 2001 movie about Bletchley Park.
Through it all, Batey remained modest about her role during the war. “I was just part of a team. We were all part of a team. The heroes,” she told London’s Daily Telegraph last year, “were the chaps who were fighting on D-Day.”
Blagg has been Editor of The Recorder since 1986. He lives in Greenfield and is a military historian with an interest in local history. He can be reached at: email@example.com or 413-772-0261, ext. 250.