Sylvia Plath and Ted Hughes had one of the most volatile and intriguing marriages of the 20th century, and 15 new letters are set to be released in a book that will give us a visceral taste of what The Bell Jar author really thought about her much maligned husband, who has been blamed by Plath’s fans for her suicide age 30 in 1963.

The new letters make one thing clear – Plath, from the time her and her poet husband met in 1956, was hopelessly, desperately, and perhaps dangerously in love with Hughes. “I think if anything ever happened to you, I would really kill myself…” she wrote in one letter.

And in another: “I honestly believe that by some mystic uniting we have become one flesh; I am simply sick, physically sick, without you. I cry; I lay my head on the floor; I choke, hate eating; hate sleeping, or going to bed… I am living in a kind of death-in-life…”

Serialised in The Telegraph, the letters chronicle a time when the pair were separated after Plath left Yorkshire to begin her second year of study at Cambridge University. Over three weeks in October 1956, Plath wrote passionately to Hughes almost every day.

Frieda Hughes, one of the pair’s two children, had kept the letters in a personal collection unknown to Plath scholars since 1968.

She writes in the foreword that despite the negativity surrounding their relationship, her father was her mother’s biggest champion. “It has always been my conviction that the reason my mother should be of interest to readers at all is due to my father, because, irrespective of the way their marriage ended, he honoured my mother’s work and her memory by publishing Ariel, the collection of poems that launched her into the public consciousness, after her death.

“He, perhaps more than anyone, recognised and acknowledged her talent as extraordinary. Without Ariel, my mother’s literary genius might have gone unremarked forever. Although, by ensuring her work got the attention it surely deserved, my father also initiated the castigation that was to hound him for the rest of his life.”

Claims of Ted Hughes’ mistreatment of Plath were buoyed on earlier this year by a haul of letters from Plath to her psychiatrist which suggested that Hughes had emotionally and physically abused her. Plath alleges that Hughes had physically abused her shortly before she miscarried their second child in 1961. Plath also claimed in another letter, dated a month later, that Hughes had told her that he wished she was dead. The letters also detail Plath’s feelings about Hughes’s infidelity with their neighbour Assia Wevill in July 1962.

Plath appears to be having a bit of a renaissance in 2017, as another new book, These Ghostly Archives, picked over unearthed letters, photographs, poems and manuscripts earlier this year. In 2018 a Bell Jar film, starring Dakota Fanning, is set to be released. 

The Letters of Sylvia Plath Volume I: 1940–1956, will be published by Faber 28 September