WS Merwin, a prolific and versatile master of modern poetry who evolved through a wide range of styles as he celebrated nature and condemned war and industrialism died on Friday, aged 91. A Pulitzer Prize winner and former United States poet laureate, Merwin completed more than 20 books in his career, from early works inspired by myths and legends to angry protests against environmental destruction and the conflict in Vietnam to late meditations on age and time. He wrote rhymes and blank verse, a brief report on the month of January and a book-length story in verse about colonialism and the birth of modern Hawaii. Like his hero, Henry David Thoreau, he was inspired equally by reverence for the planet and anger against injustice. He died in his sleep at his home on the Hawaiian island of Maui, according to publisher Copper Canyon Press and the Merwin Conservancy, which the poet founded. "He is an artist with a very clear spiritual profile, and intellectual and moral consistency, which encompasses both his work and his life," fellow poet Edward Hirsch once said of him. Merwin received virtually every honour a poet could ask for - more, it turned out, than he desired. In protest of the Vietnam War, he declined a Pulitzer in 1971 for <em>The Carrier of Ladders</em>, saying he was "too conscious of being an American to accept public congratulation with good grace, or to welcome it except as an occasion for expressing openly a shame which many Americans feel". William Stanley Merwin was born in New York City in 1927. He soon moved to Union City, New Jersey, living for years on a street now called WS Merwin Way, then to Scranton, Pennsylvania. In a long, autobiographical poem, <em>Testimony</em>, he remembered his father as a weary, disappointed man, subsisting on "pinched salaries" and "travelling sick with some nameless illuminating ill". His mother was orphaned early in life and grieved again when her baby, a boy she meant to name after her father, died "when he had scarcely wakened". In a household as grim as an abandoned parking lot, the way out was pointed by words, which seemed to float around Merwin like magic bubbles. He would try to memorise scripture he heard his father recite and fairy tales his mother told him. By age 13, he was already composing hymns. He received a scholarship from Princeton University, becoming the first family member to attend college, and began meeting some of the great poets of the present and future. Galway Kinnell was a classmate at Princeton and John Berryman a teacher. After graduating, he lived in Spain and tutored the son of Robert Graves, and in London he was friends with Sylvia Plath and Ted Hughes. Merwin's promise was obvious. His first collection, <em>A Mask for Janus</em>, was selected by WH Auden for the coveted Yale Series of Younger Poets competition and was published in 1952. Throughout the 1950s, he wrote poems and plays, including a verse production of <em>Rumpelstiltskin</em>. Times spent in Boston with Robert Lowell convinced him to concentrate on poetry, and by the end of the decade, he was regarded as a highly talented artist immersed in Old English literature, his verse likened by <em>The New York Times </em>to "a broad river flowing through peaceful land". By the early 1960s, he was marching against nuclear weapons and throwing off the rules of grammar, inspired by his "growing sense that punctuation alluded to an assumed allegiance to the rational protocol of written language". Meanwhile, Vietnam and urbanisation darkened his vision. "I/can hear the blood crawling over the plains," he wrote in <em>The Child</em>. In <em>The Crust</em>, the downfall of a tree is a metaphor for the severing of civilisation: "And with the tree went all the lives in it that slept in it ate in it met in it believed in it." In the 1970s, he settled permanently in Hawaii and studied under the Zen Buddhist master Robert Aitken. Divorced years earlier from Dorothy Jeanne Ferry and from Dido Milroy, he married his third wife, Paula Schwartz, in a Buddhist ceremony in 1983. She died in 2017. Merwin's work became sparer, rooted in the Hawaiian landscape and his personal past - how it's often forgotten, how it's never understood at the moment it's lived, how words themselves were imperfect bridges to lost time.