Queen Frederica Louisa (1751-1805) was the daughter of Ludwig IX, Landgrave of Hesse-Darmstadt. In 1769, she married, as his second wife, King Frederick William of Prussia, miniatures of whom are also in the Royal Collection (RCIN 420504 and 420500). When the Swedish Princess Hedwig Elizabeth Charlotte visited Frederica in 1798 she described her as small and plump, so that 'You could mistake her for one of these fairies from an ancient tale. She is very polite and talkative and shines of a goodness' with 'a kind heart and a noble character'.

The miniature is probably copied from a half-length portrait by Johann Heinrich Schröder in the Royal Collection (VR inv. 739).

The gilt back of the original locket is preserved within the case and inscribed in ink: Friederike / Köningen von / Preussen / geb. Prinzessinn / von / Hessen Darmst: / Gemahlin König / F.W. II (Frederica / Queen of / Prussia / born Princess / of Hesse-Darmstadt / wife of King / F. W. II).