Mad, bad and darling to know

Riots and protests by the disaffected poor with the looming spectre of "mob rule", have often troubled MPs and lords at Westminster.

No lawmaker, though, has ever raised his voice on behalf of the mutinous have-nots as boldly as one 24-year-old peer did during his maiden speech in the House of Lords on 27 February 1812. Over the previous nine months, the Luddite revolt against new technology in the weaving trades that boosted profits but eliminated jobs had spread through the villages of the young lord's native Nottinghamshire. Under cover of darkness, unemployed stocking-weavers moved from workshop to workshop, smashing the "wide frames" that had wrecked their livelihoods and starved their families.

In panic, the Tory government had sent in the troops to put Nottingham and the surrounding districts under virtual martial law: 1,000 infantry and 900 cavalry in December 1811; two more regiments in January. Then it turned to the criminal statutes. On 21 February the Frame Work Bill, which made frame-breaking a capital crime, passed the House of Commons. When it came before the Lords, who better to speak on the subject than the noble possessor of Newstead Abbey, unexpectedly inherited in 1798? From his country seat, he could almost see the flames of the rioters.

Few people then knew much about George Gordon, the sixth baron Byron. Although he seemed to favour the Whigs rather than the Tories, fellow-peers might have expected a show of class solidarity. What they got was a revolutionary bombshell, and a theatrical coup that set the tone for the next astonishing weeks in Byron's life.

By April 1812, the lame and feckless drifter from an eccentric Scottish family had redefined the nature of literary stardom. He had more or less fixed the modern meanings of celebrity. And he was well on the way to becoming (after Napoleon Bonaparte, whom he revered) the most admired and influential European figure of the 19th century, a byword for artistic audacity and sexual adventure.

This month, the Jermyn Street Theatre revives Howard Brenton's play Bloody Poetry, which dramatises the torrid ménage à quatre that Byron hosted on the shores of Lake Geneva in 1816, along with Percy and Mary Shelley and his lover, Claire Clairmont. Such scandals fixed the "Byronic" as a style of life as well as poetry. But his career of thrilling heresy had begun in, of all places, the House of Lords.

Byron's month of miracles – and madness – started with his outrageous defence of the Luddites.

Even Byron mocked his own oratory as "perhaps a little theatrical". His biographers tend to agree that his barnstorming showmanship proved he had no future in politics. In one respect, though, he fulfilled a promise – not to local folk, but to one in particular.

A damp squib in Parliamentary terms, the Luddite apologia showed off all Byron's nascent flair for the grand gesture, the flamboyant entrance, the shocking heresy. A few days later, his career as a poet – and cultural superstar – took off like a rocket. By 10 March, his friend John Murray had published the first two Cantos of "Childe Harold's Pilgrimage": the disguised autobiographical epic in Spenserian stanzas that he had begun in 1809.

Byron, as he wrote, "woke up and found himself famous". "With a single poem," writes Phyllis Grosskurth (along with Fiona MacCarthy, the best of his modern biographers), he "had achieved a sort of celebrity and attention beyond his wildest dreams". Sexy, defiant, smouldering, rebellious, idealistic, melancholic: the vagabond hero of "Childe Harold" created the prototype of the Romantic hero that not only outlived his century but, in avatars from James Dean to Che Guevara, lasted through the next.

By 1816, the 10 editions of the first two Cantos had together sold perhaps 20,000 copies, but never in cheap editions. At first, that overnight fame opened smart salon doors to Byron in aristocratic London. Mass adulation came later.

When it comes to rock-star charisma, Byron wrote the book – and lived out its precepts. Imploring letters flooded in from swooning female admirers, demanding locks of hair, meetings, trysts, marriages. The "Childe Harold" fan archive reveals a hidden continent of loneliness, fantasy and sheer neediness. Nothing like this had ever happened in Europe before. "The subject of conversation, of curiosity, of enthusiasm," wrote the Duchess of Devonshire, "is not Spain or Portugal, Warriors or Patriots, but Lord Byron." As women pursued him, so the myth of the Byronic seducer took shape, and the bisexual poet could try to flee the homoerotic feelings that had shaped his affections in youth.

Byron now ascended a high-speed social escalator. Melbourne House in Whitehall, the labyrinthine, scandal-haunted London home of the raffish Melbourne clan, became his favourite haunt. With the wordly-wise grande dame Lady Melbourne,, he struck up one of the warmest friendships of his life. Lady M had two younger relations who would in complementary ways alter the course of Byron's life. Her daughter-in-law, married to her son William, was Lady Caroline Lamb. And her niece Annabella Milbanke would (disastrously for her and for him) become Lady Byron.

Byron first met Lady Caroline in early March at Holland House. Soon he and his "fan of fans" (according to MacCarthy) had begun one of the stormiest, perhaps silliest affairs of the age. Byron blew hot and cold but, by April, could write to her as "the cleverest, most agreeable, absurd, amiable, perplexing, dangerous, fascinating little being that lives".

But only in the autumn did he consider Annabella a likely partner. Without the Caro roller-coaster, maybe Byron could have avoided the drawn-out house of horrors that was marriage to Annabella. For Grosskurth, "He loved the thrill of living on the edge, but another part of him craved acceptance, respectability, and a quiet indolent life." That he never found – except, perhaps, with Teresa Guiccioli, his long-term mistress in Italy, before the final adventure in the cause of Greek independence that would end in his death in 1824.

'Bloody Poetry', Jermyn Street Theatre, London SW1 (020 7287 2875) to 25 February