For this new edition of the monograph that Gerald M. Ackerman devoted to the life and work of Jean-Léon Gérôme - now a reference book that includes two parts, a critical biography and a catalogue of paintings, prints and sculptures - the author has revised and, if necessary, modified the text whilst updating the catalogue. The study of the artist's life is based on three ancient monographs, memories of students and friends, a large number of public and private archives, as well as reading the press of his time. The catalogue is the result of more than twenty-five years of research. Some ninety works unknown at the time of the first edition were thus added to those which had already been recorded thanks to ancient sources, contracts with the State, sales catalogues, catalogues of museums and a correspondence with the collectors, as well as ninety others then held for lost. As for the previously known works, the numerous changes of ownership and localization since then have been indicated. The number of illustrations in the catalogue has been considerably increased; many dates have been corrected. The colored plates included in the text illustrate in abundance the works hitherto unknown and, much more numerous than in the first edition, show the great diversity of the master's work, thus offering us a new image of Gérôme, a new light on his talent, his interests and his masterful inventiveness. Text in French.