LONDON.- In 2006 the late Sir Denis Mahon, a renowned Caravaggio scholar then aged ninety-six, bought at Sotheby’s in London for just £50,400 a version of the painter’s famous Cardsharps in the Kimbell Art Museum, Texas. He then announced that the canvas was not by a ‘follower’ of the artist, as Sotheby’s had stated, but was in fact Caravaggio’s first version of the Kimbell masterpiece. When the story broke, the press announced that the painting ‘may be worth up to £50m’. Shocked by the news, Lancelot Thwaytes, who had consigned the painting to Sotheby’s, sued the auction house for negligence.

The case came to trial at the High Court in London in 2014. The verdict had far-reaching implications for the way experts at auction houses catalogue paintings, for understanding the role of connoisseurship in establishing authenticity and for the use and misuse of technical evidence in determining the authorship of a work of art.

This detailed account of Thwaytes v. Sotheby’s is told from the inside by an eminent art historian who acted as an expert witness in the case. He was instructed to tell the court if the Cardsharps in the Kimbell is an original, if the Mahon version is an original or a copy and, if original, whether it was painted by Caravaggio. As a result, a question that has been much debated by scholars – whether or not Caravaggio made replicas of his own paintings – ended up becoming a judicial matter.

Richard Spear, Affiliate Research Professor at the University of Maryland, College Park, is a specialist in Italian baroque painting. His principal publications include Caravaggio and his Followers, Domenichino and The ‘Divine’ Guido: Religion, Sex, Money and Art in the World of Guido Reni. He co-edited Painting for Profit: The Economic Lives of Seventeenth-Century Italian Painters, the basis of his most recent book, Dipingere per profitto: Le vite economiche dei pittori nella Roma del Seicento. While teaching at Oberlin College, he directed the Allen Memorial Art Museum and served as Editor-in-Chief of the Art Bulletin. Among his many awards are grants from the Fulbright Program, the American Council of Learned Societies, the National Endowment for the Humanities, the Center for Advanced Study in the Visual Arts, the National Humanities Center and the Guggenheim and Rockefeller foundations.