Ariel was the second book of Sylvia Plath's poetry to be published. It was first released in 1965, two years after her death by suicide. The poems of Ariel, with their free-flowing images and characteristically menacing psychic landscapes, marked a dramatic turn from Plath's earlier Colossus poems.
The work's editor, Ted Hughes, made substantial changes to Plath's intended plan for the collection by changing her ordering of the poems, dropping some pieces, and adding others. The first American edition was published in 1966 and included an introduction by the poet Robert Lowell. This was appropriate, since, in a BBC interview, Plath cited Lowell's book Life Studies as having had a profound influence over the poetry she was writing in this last phase of her writing career. In the same interview, Plath also cited the poet Anne Sexton as an important influence on her writing during this time since Sexton was also exploring some of the same dark, taboo, personal subject matter that Plath was exploring in her writing.
In 2004, a new edition of Ariel was published which for the first time restored the selection and arrangement of the poems as Plath had left them; the 2004 edition also features a foreword by Frieda Hughes, who is the daughter of Plath and Ted Hughes.