Ted Hughes and the Birthday Letters

When Ted Hughes (pictured) published his critically acclaimed poems Birthday Letters, which recorded his relationship with his first wife Sylvia Plath, they were a publishing sensation, selling more than 500,000 copies. At the time critics wondered why he waited so long to examine this most emotional of subjects – Plath, of course, committed suicide after the former Poet Laurate began an affair with another women – and so, it transpires, did he.

In a letter to fellow poet Katherine Raine written just months before he died in 1998, Hughes laments the fact that he kept his feelings about her buried and admitted that was a mistake. He wrote: "I think those letters do release the story that everything I have written since the early 1960s has been evading. It was in a kind of desperation that I finally did publish them - I had always thought them unpublishably raw and unguarded, simply too vulnerable. But then I just could not endure being blocked any longer. How strange that we have to make these public declarations of our secrets. But we do."

For 35 years feminists accused the philandering Hughes of driving the American poet to suicide - some even accused him of her murder. While Plath wrote "confessional poetry", Hughes kept his feelings about her buried for half his life. Poignantly, he adds: "If only I had done the equivalent 30 years ago, I might have had a more fruitful career - certainly a freer psychological life."

The Raine letter is one of many included in an archive of more than 220 files and boxes of notes, journals and manuscripts that the British Library has just purchased for £500,000 from the late Poet Laureate's surviving widow Carol.