John Keats, the poet of "beauty", a devotee of aesthetic isolation who swooned at the thought of his so-called "bright star" Fanny Brawne and succumbed to TB when he was 25, was an opium addict.
The claim is made in a new biography, to be published on Monday, by Prof Nicholas Roe, chair of the Keats Foundation and a fellow of the Royal Society of Edinburgh.
Roe admits his finding will be contentious. "This has never been said before: Keats as an opium addict is new," he said.
Roe, professor of English literature at the University of St Andrews, dismisses other experts who have previously concluded that Keats only briefly experimented with the drug. The former poet laureate Andrew Motion, winner of the Whitbread prize for biography and author of a biography of the poet, has, said Roe, made "assumptions" about Keats and his use of opiates that "simply have no warrant".
"Andrew Motion's line was that [Keats' close friend] Charles Brown warned Keats about the 'danger of such a habit' and asked Keats to promise 'never to take another drop without [his] knowledge'," said Roe. "But on no evidence that I can find, Motion surmises that 'Keats did as he was told'," said Roe.
"My biography takes the contrary view that the spring of 1819 was not only one of Keats's most productive periods but also his most heavily opiated. He continued dosing himself to relieve his chronically sore throat; and that opium-induced mental instability helps to explain his jealous and vindictive mood swings regarding Fanny Brawne," Roe added. Motion said he has "admiring feelings" about Roe's book, which he has read, and agreed it is "possible that [Roe] is right about this even though I said differently in my book".
However, he added, "it is quite striking that there is no hard evidence in the letters of Keats or his friends, as there is in those of Coleridge".
Motion also said that because Keats – who "by that kiss" vowed "an endless bliss"– had briefly taken laudanum in his youth and had seen the effect of it on others when he was a medical student, "it's not beyond the bounds of possibility that he explored [the effect of the drug in his poems] from these remembered experiences rather than from a full-on vantage point. "Nick is making assumptions, just as I made assumptions," he said. "That's all we can do, because there is no hard evidence either way."
But Roe said he is convinced that Keats' most famous poems, Ode on Indolence and Ode to a Nightingale, arose from opium reveries. "This explodes entrenched conceptions of him as a delicate, overly sensitive, tragic figure," said Roe. "That Keats was using opium to enhance what it meant to 'fade far away, dissolve, and quite forget' the world gives us a different Keats: a Keats whose struggle with life was more complex, and darker than we have previously thought.
"Keats's odes of spring 1819 have often been read as his most 'philosophical' engagement with the intractable contraries of beauty and mortality, time and eternity," added Roe. "To find those two odes and, I suspect, La Belle Dame sans Merci, arose from opium reveries gives us a less intellectual or 'philosophical' Keats, and a poet who is closer to the mystical aspects of Romantic tradition associated with Blake, Baudelaire, Coleridge, De Quincey, Yeats, Huxley and Bob Dylan."
In his book John Keats, published by Yale University Press, Roe claims that "to be 'half in love with easeful death'," as Keats wrote in Ode to a Nightingale, is the hallmark of the confirmed addict.
Roe maintains that Keats, a trained physician, gained access to laudanum in the autumn of 1818 while administering the drug to his brother.
Tom was dying of TB, the disease he gave to Keats and of which the poet died three years later. Opium was the only painkiller that could alleviate the young man's pain.
After his brother's death, Keats began taking the drug regularly "to keep up his spirits", as Brown said later. Brown warned him of the "danger of such a habit". This, said Roe, "suggests Keats was indeed an 'habitual' user of opium and had been dosing himself for a considerable time."
Roe believes Keats's poem Ode on Indolence was written during an opium addiction that, he said, "was as intense as ST Coleridge's".
"When Keats writes in Ode to a Nightingale of having 'emptied some dull opiate to the drains' he means – very precisely – downing a decanter of laudanum," he said.
"Like Coleridge's Kubla Khan and like Thomas de Quincey's Confessions of an English Opium-Eater, Ode to a Nightingale is one of the greatest re-creations of a drug-inspired dream-vision in English literature – a poem that frankly admits his own opium habit."
Ode on Indolence, added Roe: "grew out of a reverie induced by taking laudanum to ease the pain of a black eye, got while playing cricket on Hampstead Heath in March 1819".
Keats's continued use of opium is, Roe claimed, "apparent from his up and down moods, and the increasing turmoil of his relationship with Fanny Brawne in 1820, a phase of his life that resembles Coleridge's opiated anguish over his unrequited passion for Wordsworth's sister-in-law, Sara Hutchinson, in the years 1802 to 1804".
He added: "The final, tragic twist of this story [comes] when Keats and the young painter Joseph Severn were voyaging to Naples, en route, they hoped, to find a cure for Keats's TB."
On the trip, Severn refused to let Keats take laudanum and hid the bottle. "As a result, Keats endured the protracted suffering of pulmonary consumption and faced his death without the panacea that had helped his brother and called into being some of the greatest poetry in the language," said Roe.
Richard Holmes, author of The Age of Wonder: How the Romantic Generation Discovered the Beauty and Terror of Science, said Roe's book is "an astonishingly fresh and observant new biography.
"It is meticulously researched ... and makes us see the poet from multiple angles, in all his fierce contradictions, so sympathetic and so modern," he added.
The poet and professor Christopher Reid, author of A Scattering, agreed. "[Roe's] radical, restless Keats is a wholly convincing and endearing portrait," he said.