Elizabeth Ross, Bletchley Park codebreaker who acted with Gary Lineker in her 90s – obituary

Elizabeth Ross, who has died aged 98, broke Japanese codes at Bletchley Park during the Second World War before going on to become an actress, memorably upstaging Gary Lineker in a Walkers crisps TV advert.

Shortly after beginning a degree in Medicine at Oxford in 1944, she was recruited, along with a number of her friends at Lady Margaret Hall, to work as “clerks at the Foreign Office”.

Sent to Bletchley, they were among a number of female university students and graduates brought in to help break Japanese codes and ciphers as the British codebreakers increased their focus on the war in the Far East.

Ross was given a six-week course in Japanese before being put to work in “Hut 7”, which although named after the solitary wooden hut in which Japanese naval codes had originally been broken was now a very large division based in Block A, one of a number of new sprawling concrete buildings constructed as the number of codebreakers expanded with the war.

“I was conscripted after one year at Oxford University reading Medicine, along with a friend, Félicité Berryman,” she recalled. “We were both sent to Hut 7 to work on the JN40 merchant-shipping code. It changed every month and once you had broken it you could set up the grids for the next month.”

With the war in the Far East conducted across a number of countries in the Pacific and Indian Oceans, the Japanese merchant fleet had been commandeered to transport supplies to Japanese forces. Their locations, cargoes and destinations provided vital intelligence to the Allied ships and submarines which were trying to intercept and sink them.

“A lot of the messages were positions, endless positions in latitude and longitude, sightings of ships. When there was a ‘rush’ on we were occasionally sent to work on JN25 [the main Japanese naval code].

“There was always great competition with the Americans on JN25. If we got some way in there was always a feeling that we shouldn’t tell them this time: ‘We can get there first. Don’t let them know about this one.’ That was always the joke, of course. We always did tell them but we always felt that we did terribly well without the machinery and vast amounts of manpower they had.”

Elizabeth Ross was always reticent about her work, scrupulously obeying the codebreakers’ oath of secrecy. Even in 1990, when she appeared as Alan Turing’s mother Sara in Breaking the Code, Hugh Whitemore’s play about the famous codebreaker, at the Latchmere, the other cast members only found out that she also worked at Bletchley when her son came to watch a performance and told them afterwards.

Recalling the intense secrecy at Bletchley, she said: “We never spoke to anyone, even people in the neighbouring offices, about what we did. It was extraordinary. You might have friends in the next office, but you would meet them outside or in the canteen. You would never visit them in the office.”

She and her friends worked on 10-hour shifts – each role was manned 24 hours a day – with no weekly day off but with a long weekend every month.

“We either hitched along Watling Street to London – the marvellous lorry-drivers always picked us up and the roads were empty of all other traffic, except military vehicles, because of petrol rationing – or we bicycled to meet friends in Oxford, sometimes spending a night.”

At the end of the war, having acted at Oxford and been part of the Bletchley Park Drama Group, Ross decided to become an actress, hitch-hiking to Nottingham for a successful audition with the actor Donald Wolfit for his Wolfit Shakespeare Company.

Elizabeth Nesta Ross was born on January 22 1924 in Kenya, where her father Sandford, or Sandy, was a member of the Colonial Service. She was educated at Sherborne School for Girls before going up to Oxford to study Medicine.

It was there that she met her future husband, John Moullin Davies. They married in 1950, and when he joined the Royal Navy as a ship’s surgeon she took a break from acting to accompany him on tours abroad and to bring up their family.

The couple had four children, and after Davies left the Navy they settled in Combe, Oxfordshire. When the children left home, Ross taught drama at Oxford High School, and when she was forced to retire at 62, she returned to the theatre, deliberately targeting the roles of old ladies because although they were frequently minor ones, “the competition was dying off.”

Aside from her appearance in Breaking the Code, her acting career included a well-reviewed portrayal of Edna, the maid, in Stephen Daldry’s ground-breaking production of JB Priestley’s An Inspector Calls, which she played in five separate productions.

The first, in 1999, when she was 75, was a nationwide tour, followed by a successful run at the Garrick Theatre in the West End. Ten years later, aged 85, she reprised the role in another West End run at the Novella, which was so successful it transferred to Wyndham’s.

Although theatre was her first love, she also appeared in a number of popular television shows including, Sorry, Miss Marple, Keeping up Appearances, Casualty, Doctors and EastEnders.

But one of her most memorable performances – and certainly the one which gave her the widest audience – was shortly before she retired, when at the age of 91, in a television advertisement for Walkers Crisps, she played an elderly lady whose stairlift is being fixed by a technician played by Gary Lineker.

When he slams his toolbox down on her finger to prevent her taking one of his crisps, she flicks a switch on the stairlift to send him flying up the stairs and out of a window, and then eats his crisps.

Elizabeth Ross’s husband died in 2008. She is survived by their two daughters and two sons.

Elizabeth Ross, born January 22 1924, died January 10 2023