After Bertel Thorvaldsen (1770-1844) Probably Italian, early 19th century

Overall the condition of the marble is good. There is minor dirt and wear to the surface consistent with age and handling, including a few nicks and scratches. There are minor casting flaws to the surface throughout. There is a larger short pore to the back of the head.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

Thorvaldsen was commissioned to sculpt a bust of Byron in 1817 by the politician, prison rights campaigner and friend of Byron, John Cam Hobhouse (1786-1869). The original plaster is in the Thorvaldsen Museum, Copenhagen (inv. no.  A256). The marble, which, like the present bronze, has a herm type truncation, is in the Royal Collection at Windsor (inv. no. 35425). Further known autograph versions include the example at Chatsworth and that sold at Christie's New York on 13th June 1987, lot 263.

RELATED LITERATURE
E. Sass, Thorvaldsens Portraetbuster, Copenhagen, 1965, vol. I, p. 318-240, vol. III, no. 79, p. 164; E. di Majo, B. Jørnaes, S. Susinno (eds.), Bertel Thorvaldsen 1770-1844: sculture danse a Roma, exhib. cat. Galleria Nazionale d'Arte Moderna, Rome, 1989-1990, no. 40, p. 175-6