A posthumous copy after Sir William Beechey's three-quarter-length oil portrait of Princess Sophia Matilda dating from c.1803 (406663; Royal Collection), engraved by E. Scriven for Bell's Court and Fashionable Magazine, sometimes called La Belle Assemblée (1806). At the time Haslem painted his copy, the original by Beechey was still in the possession of Princess Mary, Duchess of Gloucester, at Gloucester House, Park Lane, and it was not until her death in 1857 that Queen Victoria came into possession of it.

Princess Sophia Matilda, only daughter of William Henry, Duke of Gloucester, and Maria, Countess of Waldegrave. She was devoted to her only brother William Frederick, Duke of Gloucester, who married Queen Victoria's aunt, Princess Mary.