Magdalena Ross was the second daughter of William Ross, miniature painter, and Maria Smith, and younger sister of Sir William Ross, Miniature Painter to Queen Victoria. Trained as a miniaturist by her father, she exhibited at the Royal Academy from 1820  to 1856  and styled herself 'Miniature Painter to the Queen' from 1850. She also produced watercolour copies of her brother William's work for Queen Victoria, and some of these remain in the Royal Collection. A miniature of her by Sir William Ross is in the Victoria and Albert Museum, London (281-1875).

Leopold I, King of the Belgians, wrote to Queen Victoria on 30 October 1840: 'Ross is arrived and though it bores me considerable [sic] I flatter myself that he will not want many séances and that I shall then have done with him'. The result of those sittings was the large three-quarter-length miniature on which this copy by Magdalena Dalton is based. It was formerly in the private collection of King Leopold III of Belgium (present location unknown).

Signed, dated and inscribed on the reverse in ink: His Majesty / Leopold / King of the Belgians / Painted by / Miss Magdalena Ross / London 1840 and in pencil: This the Queen / will keep for / herself.