Raphael’s portrait of friend and fellow artist, the metalist and gem engraver Valerio Belli, highlights the relationship between two great Renaissance masters. Christopher Apostle, Head of Sotheby’s Old Master Paintings New York, discusses this remarkable highlight from The Collection of A. Alfred Taubman: Old Masters, to be offered in New York on 27 January 2016. Visit sothebys.com/taubman.