The American poet John Ashbery has died at the age of 90. His husband, David Kermani, said the poet died early on Sunday at home in Hudson, New York, of natural causes.

His 1975 collection Self-Portrait in a Convex Mirror won the Pulitzer prize, the National Book award, and the National Book Critics Circle prize. He published more than 20 volumes of poetry, and has been described one of the greatest 20th century American poets. 

Ashbery’s first book, Some Trees (1956) won the Yale Younger Poets prize. The competition was judged by WH Auden, who confessed later that he hadn’t understood a word of the winning manuscript.

Ashbery, widely regarded as both brilliant and baffling, once told the Times newspaper: “My poetry imitates or reproduces the way knowledge or awareness comes to me, which is by fits and starts and by indirection. I don’t think poetry arranged in neat patterns would reflect that situation.”

Ashbery's poetry was described by the Poetry Foundation as challenging readers "to discard all presumptions, about the aims, themes, and stylistic scaffolding of verse". Critics noted how Ashbery's verse has been influenced by abstract expressionism, a movement in modern painting stressing non-representational methods of picturing reality. But Ashbery's poetry evolved under a variety of influences, to become the expression of a voice unmistakably his own.

Writing in The New Yorker, Paul Muldoon said: "Ashbery himself was the first to be amazed at how a figure who so resolutely argued against convention, the quintessential outsider, came to occupy a central position in American poetry. It seems that he almost singlehandedly not only changed the rules of the game but also remapped the field on which the game was played.

"He managed this by developing a poetry that was absolutely equal to our later-twentieth-century/early-twenty-first-century predicament. It’s a simple argument: a world that is complex requires a poetry that is complex; a world that is somewhat incoherent may actually demand a poetry that is itself incoherent; a world in which no conclusions apply may even revel in its inconclusiveness."

'Self-Portrait in a Convex Mirror', by John Ashbery

PHOTOGRAPH: THE POETRY FOUNDATION