‘Why, Elizabeth, did you not tell me when we first slept together that you were a virgin?’ This is one of the most peculiar letters in English literary history, written in 1934 by the writer Humphry House to Elizabeth Bowen, now widely recognised as one of the major novelists of the 20th century. Bowen was 34 and had been married for ten years when she first went to bed with House in 1933. It’s not surprising that he shouldn’t have expected her to be a virgin, though his rendition of their encounter is bafflingly obtuse: ‘I thought you had some malformation… had I known… how much less gloom would have sat across that breakfast tray!’

The story of Bowen’s affair with House was under wraps for years. Bowen’s first biographer, Victoria Glendinning, wasn’t allowed to name him. Subsequent biographers have done more with the affair, and now House’s granddaughter, Julia Parry, has given the fullest account yet in an original book that’s partly an edition of their letters and partly a description of her travels in her grandparents’ footsteps. Parry is a spirited narrator who is clearly a great admirer of Bowen’s fiction but isn’t blindsided by this, remaining admirably nuanced as she gives a judicious moment-by-moment account of these complicated characters over the decades.

This is a story of sexual freedom. House was the first of several men with whom Bowen had affairs during her marriage to Alan Cameron, all younger than her, all literary, with fine bones and high foreheads. She had affairs partly because she was sexually unsatisfied in her marriage and partly because she needed intense experience as a background to her novel writing. She described herself in one letter to House as ‘a writer before I am a woman’. For his part, House’s sexual urges tended to lead him in several directions at once. Shortly before getting married, he wrote to his fiancée: ‘I cannot cure myself, even now our marriage is settled, of violent and casual physical attraction to all kinds of women whom I meet.’

It is also a story of sexual exploitation. This is the first time House’s wife Madeline has emerged as a character in her own right. She takes centre stage in Parry’s book, because she is the only one of the cast who Parry knew. As a result, we see the full implications of House’s caddishness, including his lack of curiosity about Madeline’s considerable mind. Far from being the meagre housewife her husband sometimes saw her as, Madeline was a courageous woman who went to university at a time when few women did, got a job working in the London slums (helping families follow the advice of health workers) and travelled to Germany alone shortly before her marriage.

Bowen didn’t help House to appreciate his wife. After meeting her for the first time (House engineered a sherry-drinking session for the two women alone), Bowen wrote to House lamenting his fiancée’s lack of personality. And she allowed herself to be made use of as well, lending her house in Ireland to him at the same time as Madeline loaned him money, and spending several years tediously at the ready for his occasional visits when he needed respite from his domestic life.

As a portrait of a 1930s marriage, this is illuminating, especially perhaps in revealing how much the enlightened, bohemian-cum-aristocratic values of the interwar period allowed for the perpetuation of a very old-fashioned kind of patriarchy. House was open in being far less enamoured of his young daughters than he was of his son. He left Madeline to the business of rearing his children to the extent that he moved to India shortly before the birth of their second child (‘this is no country for a wife’ he wrote home to Madeline by way of warning) and didn’t meet her until she was walking and talking.

The story is redeemed by Madeline’s quietly resolute independence. Though she heeded her husband’s warnings not to bring the children to India, she decided to go herself, leaving them with her parents for several months while she visited him. She then became a collaborator with him on an edition of Dickens’s letters, which she brought to publication after his death.

And it’s redeemed too by Bowen’s strength and depth. These aren’t works of art in the way her best letters to later lovers were, but we can see her feeling her way into the emotional landscape she would come to inhabit. This is a woman learning that she can be the more powerful one in a relationship even (or especially) when she’s the one who allows herself to feel more. House may equivocate or preen, and she occasionally succumbs to pettiness in relation to Madeline, but she emerges triumphant nonetheless, rightly sure of her own capacity for feeling and insight.