These four reliefs can be attributed to the Flemish sculptor Gaspar van der Hagen, who came to London and was a long-term assistant to Michael Rysbrack. Three of the reliefs are after busts by Rysbrack while the fourth - of Shakespeare - is from the full-length marble executed by Rysbrack's contemporary, Peter Scheemakers, for the playwright's monument in Westminster Abbey. In 1747 the engraver and antiquarian George Vertue noted 'Mr. Vander Hagen. Sculptor works for Mr Rysbrack. has done several heads portraits in Ivory. - very well.' Other examples of van der Hagen's work in ivory, signed with different monograms, have appeared on the art market, including four oval portraits of Milton, King Alfred, Queen Elizabeth and Cromwell sold at Sotheby's London, 8 December 1988, lots 398-401.