Trained as a doctor, Keats was only 24 when he read his doom (“my death-warrant; I must die”) in a handkerchief spotted with bright arterial blood. The brilliant contemporary of Shelley and Byron in the second generation of Romantic poets, John Keats died 200 years ago, aged 25. His lungs were already so ravaged by tuberculosis that the doctors in Rome — a warm climate offered a last faint chance of recovery — couldn’t believe he had survived so long.

High though his hopes of public fame had been, Keats asked to be buried without an identifying name and with the poignant epitaph: “Here lies one whose name was writ in water”. Overlooking the fact that Keats apparently fell into a pleasant sleep after choosing these words, his travelling companion, Joseph Severn, conspired with the poet’s friend Charles Brown and his publisher, John Taylor, to enshrine them on the gravestone as an expression of “the Bitterness of his Heart, at the Malicious Power of his enemies”.

The idea was Taylor’s; Brown later saw the added words as a “profanation”, and Severn, as an “eyesore”. Keats, a generous and exceptionally unbitter man, had in fact robustly withstood and even laughed at the ill-informed sneers of his critics.

One of the main achievements of Lucasta Miller’s enlightening guide to the poems and their creator is to banish the sentimental image to which Shelley’s “Adonais” — published just a few months after Keats’s death by a poet who scarcely knew him — contributed much with its self-serving lament for an ethereal spirit destroyed by a hostile press.

A more recent representation of the Keats who never was — wittily slapped down by Miller — emerged from Jane Campion’s film Bright Star (2009), in which a sensitive, nature-loving Keats was outshone by a maidenly Fanny Brawne, weeping her eyes out at the news of his death (the sobs go on and on) before spending three nunlike years in widow’s weeds. The actual Fanny kept up a lively correspondence with Keats’s sister, her namesake, before marrying a much younger man and settling abroad. Romantic biopics are notoriously keener on beauty than fidelity to truth.

Nicholas Roe’s scholarly and succinct John Keats: A New Life (2012) remains definitive. Miller’s approach works perfectly for a general reader like myself, using nine of Keats’s best-loved poems to guide us from the dazzled explorer standing “Silent, upon a peak in Darien” (in his early “On First Looking into Chapman’s Homer”) to tender homage in “Bright Star” to Fanny Brawne: (“I will imagine you Venus tonight”, Keats wrote to his capricious “Minx” from the Isle of Wight).

Fondly familiar with Keats’s homes and favourite strolls, Miller draws on her experience as a fellow north Londoner to summon him up: a short, energetic, broad-shouldered young man who often jokingly signed himself as “Junkets” in some of the most bewitchingly conversational letters of the Romantic Age. When Miller’s Keats strolls across Hampstead Heath with Coleridge, his famously loquacious neighbour, we feel no surprise that the older poet instantly invited him home — or that Keats managed to resist the temptation.

A young man in a hurry is the figure whom Miller sets convincingly before us, too hasty to care about his spelling (“smoak’d . . . a Segar”), too conscious of his mortality — Keats was eight when his father died; 14 when he nursed his dying mother; 23 when he performed the same service for a beloved younger brother — to allow harsh reviews to hold him back.

The poetry, once he had quit a burgeoning career in medicine, flowed with deceptive ease from what Keats once memorably called a “teeming brain”. It’s thrilling to follow Miller’s demonstration of how the rapidly written “Ode to a Nightingale” (possibly heightened by laudanum) evokes images, just as Schubert’s music uses notes, to express the indefinable. It’s startling to learn how uncertain a judge Keats was of his own work, dismissing the glorious Odes and omitting the haunting “La Belle Dame sans Merci” from his third and final collection.

Yeats once summarised Keats (whom he greatly admired) as “poor, ailing and ignorant”. Miller follows Roe in reminding us just how wrong Yeats was. “Poor”, when the Keats siblings’ tangled legacy (from a wealthy grandmother) inspired Dickens’s Bleak House account of the interminable Jarndyce v Jarndyce case? “Ignorant”, applied to a prize-winning scholar whose education at Charles Clarke’s renowned academy at Enfield outranked Byron’s at Harrow, or Shelley’s at Eton?

Here, and elsewhere, Miller disrobes the myth, while helping us to appreciate what she calls Keats’s “vertiginous originality”. As a wittily perceptive introduction to (or reminder of) the poet and his work, her book is unlikely to be surpassed any time soon.

Keats: A Brief Life in Nine Poems and One Epitaph by Lucasta Miller Jonathan Cape £17.99, 368 pages

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