E. P. Shirley. Stemmata Shirleiana; or the Annals of the Shirley Family. London, 1841, pp. 213–14 [2nd ed., 1873, p. 278], identifies the sitter as Sir John Shurley of Isfield, who married Sir Anthony Shirley's sister Jane, "on which occasion it was painted".
John Bernard Burke. A Visitation of the Seats and Arms of the Noblemen and Gentlemen of Great Britain and Ireland. London, 1854, 2nd ser., vol. 1, p. 31, as a portrait of Sir Anthony Shirley, ambassador from Persia in the reign of Queen Elizabeth.
Bernard Burke. The General Armory. London, 1883, p. 924, Shirley, or Sherley [Isfield, co. Sussex; extinct]. Arms, granted temp. Henry VIII. Paly of four az. and gu. three stags' heads couped ar. on a fess wavy or, three cornish choughs ppr.; but the family afterwards assumed and were allowed in the Visitations, Paly bendy of eight ar. and az. a canton erm.
Sidney Lee in Dictionary of National Biography. Vol. 18, New York, 1909, p. 123, as in the collection of Sir Thomas Western, Rivenhall, Essex; states that although it is usually called a portrait of Sir Anthony Shirley it is actually a portrait of his brother-in-law, Sir John Shurley.
Ellis Waterhouse. Letter to Elizabeth Gardner. May 7, 1952, calls the attribution to Zuccaro quite impossible, observes that the idea that the "hieroglyph" below the helmet may in fact be a signature should not be disregarded, imagines the painter to be of Flemish origin.
John Guinness. Letter to Elizabeth Gardner. January 14, 1957, provides 1632 as the death date for Sir John Shurley of Isfield.
David Piper. Letter to Mrs. H. D. Allen. February 5, 1957, believes that it is definitely by the same hand as a portrait of Admiral Cavendish at Longleat.
Roy Strong. Letters to Elizabeth Gardner. 1962–63, considers it likely that "the H monogram stands for Hubbard, one of the most fashionable and the most elusive of Elizabethan portraitists," and that it is by the same hand as a portrait of Sir Walter Raleigh at the National Portrait Gallery, London.
John Sunderland. Letter. October 4, 1967, reports that Mr. Norman of the Wallace Collection identifies the armor as Italian and states that the artist is unlikely to be Zucchero.
Roy Strong. Tudor & Jacobean Portraits. London, 1969, vol. 1, p. 256, observes that our portrait is signed H and attributes it and one of Sir Walter Raleigh in the National Portrait Gallery, London (vol. 2, pl. 505) to the "monogrammist H (? Hubbard)," a fashionable painter active in the eighties but now entirely unknown.
A. V. B. Norman. Letter to Stuart Pyhrr. May 11, 1979, based on the coat of arms, believes that the sitter is probably not John Shurley of Isfield, but rather an unidentified member of the Shurley family.
Katharine Baetjer. British Paintings in The Metropolitan Museum of Art, 1575–1875. New York, 2009, pp. 4–6, no. 2, ill. (color), identifies the sitter as Sir John Shurley of Isfield.