The sitter has recently been identified by a stipple engraving by F. Bartolozzi dated 1788, of which the first state is inscribed 'Miss Caroline Ponsonby', cf. F. B. Daniell, A Catalogue Raisonné of the Engraved Works of Richard Cosway, R.A., 1890, no.116, p.29.
Caroline, only daughter of an Irish peer, Lord Duncannon (later 3rd Earl Bessborough), and his wife Lady Henrietta, daughter of the first Earl Spencer. There is much confusion as to how Caro (as she was known) was brought up, not the least because she had a propensity for the dramatic and for creating new pasts for herself that sounded more tragic than the original. However it seems likely from records and what is known of her grandmother, the redoutable Countess Spencer, that she spent her early years and education at Devonshire house under the chaperonage of her Aunt, Georgiana, Duchess of Devonshire. It was here that Caro was first seen by William Melbourne, the second son of Lord Melbourne and his ambitious wife, Lady Melbourne. Lady Melbourne was eager to promote a match that would tie her family and their ambitions to the political power of the Devonshire House set, luckily William fell for Caro and by the time she was 17 they were married. Despite good beginnings, their marriage began to fray slightly, compounded by the fact that Caro did not get on with her mother-in-law, who found Caro's lack of discretion unacceptable. In 1812 she met George Gordon Lord Byron. He was had just published 'Childe Harolde's Pilgrimage'. They began a much recognised and indiscreet affair that lasted a tempestuous four months. Byron ended the affair much to Caro's displeasure. She then spent the next four years pursuing him. Her family packed her off to the country and urged her husband to divorce her. Byron avoided her, seeking refuge for sometime with his new mistress, Lady Oxford, and eventually marrying a cousin of Caro's husband, Annabella Milbanke. It is for this affair that she is best known, and oft quoted for coining him 'mad bad and dangerous to know,' It was perhaps a phrase as appropriate to apply to herself as Byron.