A CODEBREAKER at Bletchley Park whose work helped save countless lives in the Second World War has been immortalised in a new poster series.

Joan Clarke, who worked alongside Alan Turing, is one of 10 women to grace the 'Trailblazers' posters created by Sage UK, an accounting and small business support company.

The pioneering mathematician was played by Kiera Knightley in the 2014 film Imitation Game.

And the striking new images were unveiled to mark Women's History Month, an international celebration throughout March of women's contributions in history.

Mrs Clarke, who spent much of her life in Headington, is honoured alongside such figures as Frida Kahlo, Malala Yousafzai, Ada Lovelace and Michelle Obama.

Jacqueline de Rojas, managing director of Sage UK, said: "Having spent 30 years as a woman in tech, I’m passionate about diversity and inclusion in the workplace.

"Shining a light on success and achievement enables the next generation of women to stand on the shoulders of giants.

"In celebrating the accomplishments of these trailblazing women, we aim to inspire and empower future generations to blaze their own trails."

The daughter of a clergyman, Joan Clarke was born in South London in 1917 and went on to gain a double first degree in mathematics.

She was recruited to the Government Code and Cypher School (GCCS), a body set up in 1939 with one sole purpose: to break the German Enigma code.

After arriving at Bletchley Park on June 17, 1940, Mrs Clarke became one of just two female cryptologists working at Bletchley Park.

Her work decrypting Nazi Germany's secret communications led to her appointment as Member of the Order of the British Empire in 1946.

In her time working alongside computer scientist Alan Turing the pair became close and he proposed to her, but their engagement was short-lived.

In an interview for BBC Horizon in 1992 Mrs Clarke said: "Although it was a surprise I really didn't hesitate in saying yes, and then he knelt by my chair and kissed me.

"Next day, we went for a bit of a walk together, after lunch. He told me had this homosexual tendency. Naturally, that worried me a bit, but we carried on."

Turing ultimately broke off the engagement and in1952, Mrs Clarke married her Bletchley Park colleague, Lieutenant-Colonel J (Jock) K R Murray, a retired army officer.

After his death in 1986 Mrs Clarke moved to Headington in Oxford, where she was a respected member of the community for the rest of her life.

She died aged 79 at her home in 7 Larkfields on September 7, 1996.