Lady Caroline Lamb (1785-1828) was an English aristocrat, daughter of the Earl and Countess of Bessborough, niece of Georgiana, Duchess of Devonshire, and cousin of Anne Isabella Milbanke. She was born Caroline Ponsonby, and in 1805 married William Lamb, an up-and-coming young politician, heir to a viscountcy. In 1812, Lady Caroline embarked on her well-publicised affair with Lord Byron (the main theme of the film, Lady Caroline Lamb). It was she who described the poet as "mad, bad, and dangerous to know".
After her liaison with Byron, Lady Caroline enjoyed some success as a novelist. Her first novel, Glenarvon, was published anonymously in 1816, and included a thinly-disguised pen-picture of her former lover. She published further books, under her own name, during the following decade. In 1824, she accidentally came across Byron's funeral cortège on its way to his burial place, and this incident drove her to the verge of insanity.