Keywords: Henry Percy, Earl of Northumberland by R. Clamp, published by Edward Harding, after Silvester Harding 1792.jpg en by R Clamp published by Edward Harding after Sylvester Harding stipple engraving published 1792 1791-01-01 http //www npg org uk/collections/search/portraitLarge/mw123952/Henry-Percy-Earl-of-Northumberland LinkID mp86937 search sas sText Henry+Percy role sit rNo 1 Silvester Harding R Clamp engravers other versions PD-old-70-1923 Uploaded with UploadWizard Henry Percy 1st Earl of Northumberland 18th-century portrait engravings in the National Portrait Gallery London Silvester Harding |