The 18-year-old actress will play the lead role in Testament of Youth, based on Brittain’s heartbreaking memoir of the same name.
It follows An Education, My Week With Marilyn and Brighton Rock in a roster of period dramas from BBC Films. The project is being co-produced by David Heyman, who adapted the Harry Potter books for the big screen.
Ronan’s casting is something of a coup for the BBC. She was Oscar-nominated, aged 13, for her performance as Briony Tallis in Atonement, and more recent credits include The Lovely Bones and Hanna.
Published in 1933, Testament of Youth chronicled the devastating effect of the Great War on the author’s generation. Brittain wrote from personal experience: her brother, fiancé and two closest friends all perished in the conflict.
She became a leading figure in the pacifist movement and her treatise on the rights of women saw her hailed as one of Britain’s great feminist thinkers.
Yet she is no longer a household name, a fact BBC Films hopes will change with the new release.
“I guess it would be very much our objective to make her known again,” said Christine Langan, head of BBC Films. “This was one of the finest memoirs of the First World War, and to have one from a woman was quite unusual.”
Brittain was a fiercely intelligent young woman who defied convention - and her family’s reservations - to attend Oxford University.
But war interrupted her studies and she gave up her degree to become an auxiliary nurse in London. Seeing the terrible injuries of returning soldiers exposed her to the reality, as she put it, of “war without its glory”.
She lost her fiancé, Roland Leighton, in December 1915 and her beloved brother, Edward, in June 1918. Brittain later married and had two children, one of whom is Baroness Williams, the Liberal Democrat peer.
Her first novel, The Dark Tide, came out in 1923. But it was the publication of Testament of Youth that marked her out as one of the great writers of the 20th century.
Miss Langan said: “Vera and her friends were gilded youth and the war shattered their lives. one by one, she lost everyone she loved. The film is a story of how one survives that.”
sources: 1, 2