Lady Caroline Lamb was 27 in 1812 when she met Lord Byron, then 24, the much-fêted author of Childe Harold's Pilgrimage. Their love affair lasted only four months but Caroline's obsession with Byron lasted all her life. As late as 1820, she would insist on attending a masked ball dressed as a character from his latest success, Don Juan.
Eventually Byron married Annabella Milbanke, a cousin of Caroline's husband. Angry and vindictive, Caroline wrote the novel Glenarvon in which she satirized Byron in the character of Clarence de Ruthven. It is said that Byron had confided to Lamb his initiation into sodomy at 15 by Lord Grey de Ruthyn, then 23, a memory painful to him. Byron's characteristic response to Glenarvon was the picture can't be good – I did not sit long enough.
Polidori deliberately copied the name Ruthven for The Vampyre, because of its association with Byron, although it's unlikely he knew its history. Since then, there have been many vampire Ruthvens, although interestingly, Sheridan Le Fanu returned to Ruthyn for his evil aristocrat in Uncle Silas.
According to Annabella, Byron threatened Caroline that if she betrayed him he would, like Falkland in Godwin's Caleb Williams, persecute her to the ends of the earth. In fact, the persecution was reversed. Caroline delighted in her power and liked to remind Byron of it, once writing Remember me! in his copy of Vathek, a choice of book with obvious implications.
After Byron and Annabella separated, Caroline visited Annabella and not only told her all she knew about Byron's male lovers but confirmed her suspicions about his incestuous relations with half-sister Augusta. The public fall out from these revelations forced Byron to leave England and never return. Byron was doubtless thinking of Caroline, when he later wrote in Don Juan, sweet is revenge, especially to women.
Lamb's aunt was the notorious Georgiana, Duchess of Devonshire, author of The Sylph, who was the model for Lady Teazle in Richard Sheridan's The School for Scandal. Sheridan was briefly the lover of Caroline's mother, Lady Bessborough. When the affair became known, Bessborough filed for divorce and Sheridan's wife initiated separation proceedings. These were later dropped. For more on Sheridan see Le Fanu and Selwyn.
Caroline's husband, William Lamb, belonged to a group of Radicals that included Leigh Hunt, Percy Bysshe Shelley, William Hazlitt, Henry Brougham, Lord Byron, and Thomas Barnes. After Caroline died, Lamb (Lord Melbourne) developed a friendship with the writer Caroline Norton, who was trapped in an abusive marriage. Once Lamb became Prime Minister, Norton's husband tried to extort money from him, and when he failed, publically accused him of being his wife's lover. The ensuing scandal nearly brought down the government.
Caroline Lamb was also courted by Edward Bulwer-Lytton.
It were vain to detail the petty instances of barbarity he employed. The web was fine enough, and wove with a skillful hand. He even consulted with Lady Mandeville in what manner to make his inhuman triumph more poignant - more galling; and when he heard that Calantha was irritated even unto madness, and grieved almost unto death, he only mocked at her folly, and despised her still remaining attachment to himself. "Indeed she is ill," said Sophia, in answer to his insulting inquiry, soon after her arrival at Mortanville Priory. "She is even dangerously ill." "And pray may I ask of what malady?" he replied, with a smile of scorn. "Of one, Lord Glenarvon," she answered with equal irony, "which will never endanger your health - of a broken heart." He laughed.
Lady Mandeville is clearly modelled on Lady Melbourne, Caroline's mother-in-law and a close friend and confidante of Byron. She was instrumental in bringing Byron and Annabella together. Lady Melbourne also appears as the world-weary Lady Besford in The Sylph.
Lamb is likely the source of the character Lady Mercer, in The Vampyre who had been the mockery of every monster shewn in drawing rooms since her marriage, threw herself in his way, and did all but put on the dress of a mountebank, to attract his notice – though in vain...