Madam Sidley [graphic]Williams, Robert, active 1680-1715, printmaker[1811]eng"Portrait of Catherine Sedley, half length in an oval, hair in curls, wearing loose, low dress. Modern; published in Boydell's 'Illustrious Heads', 1811."--British Museum online catalogueTitle engraved within circular tablet on pediment beneath portrait.State from: Smith, J.C. British mezzotinto portraits.Reissue by Boydell of a plate originally published between 1680 and 1705; see British Museum online catalogue, registration no.: 1864,0813.201.Plate from: Boydell's heads of illustrious and celebrated persons. London : Printed by W. Bulmer and Co.; and published by Messrs. Boydell and Co., 1811.Sheet trimmed to plate mark.