The unknown sitter in this portrait, wearing the crimson cassock and cap of a cardinal, is depicted as a humanist scholar. Through the open window can be seen the figure of Saint Jerome, the 4th-century biblical scholar, often portrayed in medieval art as a kneeling hermit. He is identified by a broad-brimmed cardinal's hat and the lion that was his legendary companion. During the Renaissance, however, Saint Jerome was frequently shown as a cultured man of learning in his study—a representation this sitter clearly wished his portrait to suggest.The identities of both artist and sitter have long been debated. The most persuasive evidence indicates that Lorenzo Costa painted a high-ranking prelate, possibly Cardinal Bibbiena, while court painter in Mantua, a sophisticated center of humanist culture.