This example illustrates the identification of the sitter using the evidence of engraving, other known versions, and provenance.


“The delicate and beautiful ivory medallion of Sir Christopher Wren by David Le Marchand of c.1723 (NPG, 4500) was catalogued in the sale from which it was purchased as the portrait of an unknown man. It was identified by the Gallery from a rare contemporary engraving, showing the identical image, and identifying it as Wren. Further evidence was provided by a cruder version in the British Museum, a later copy by Wedgwood, and by the provenance of the NPG version; its previous owners turned out to be descendants of the architect.”


RL Ormond, ‘The National Portrait Gallery archive’, Journal of the Society of Archivists, 4 (1970), 130-136.