Pierre Signac was one of the leading mid-seventeenth century enamellists, having learned the art from Henri Toutin, who first painted portraits on a small scale in this medium. Signac travelled to Stockholm at the invitation of Queen Christina of Sweden in 1647, and made many enamel portraits of the Queen and members of her court. In Stockholm, he met Alexander Cooper, younger brother of Samuel Cooper, who taught him how to paint miniatures in watercolour on vellum, a method which he used increasingly after Cooper's death in 1660. The present miniature is painted on vellum and must date from c. 1668, as it is a variant of a miniature of Frederica Amalia, Duchess of Holstein-Gottorp painted from life when the sitter was visiting Copenhagen in 1668 (National Museum of Finland, Helsinki, no. 11). In 1665 , Queen Hedwig Eleonora, the consort of Charles X Gustavus, King of Sweden, and a princess of Holstein-Gottorp before her marriage, had asked German courts to allow Signac access to paint portraits for her collection; his visits included a stay in Gottorp and he was in Denmark from May until September 1668. Frederica Amalia, third child and second daughter of Frederick III and Sophia Amalia of Denmark, married, in 1661, Duke Christian Albrecht of Holstein-Gottorp. Inscribed on the reverse in a nineteenth century hand: Frederica Amalia Princess of Denmark wife of Christian Albert Duke of Gottorp born 1647 died 1704.