The archive of poet Ted Hughes has been saved for the nation.

The British Library has acquired the collection of more than 220 files and boxes of manuscripts, letters, journals, personal diaries and ephemera.

The Hughes archive has been sold by the estate of the late poet laureate, run by his widow Carol Hughes, for £500,000.

One of the highlights are the manuscripts relating to Birthday Letters, Hughes's collection of poems charting and exploring his relationship with his first wife, the poet Sylvia Plath. Birthday Letters attracted widespread acclaim and phenomenal sales after it was published in 1998.

The manuscripts include the drafts of unpublished and published poems in the collection, revealing in detail Hughes's creative process over 25 years.

Other highlights include working drafts and pages of detailed thoughts and reflections relating to Capriccio, Hughes's volume of poems about his mistress Assia Wevill.

Carol Hughes said: "I am confident that the British Library is an ideal home for such an important archive, a place where it can be properly conserved and made available for scholars in a way that will prove an invaluable aid to the understanding of his work."