The article is devoted to the creative history of the novel "The Obedient Spouse Grizelia", as well as the influence on "The Useful and Edifying Stories" by G. Fernandes Trancoso of earlier examples of European Renaissance novellistics. Considerable attention is paid to the composition of "Useful and Edifying Stories", as well as the interpretation of the source (10th novel of the 10th day of "Decameron" by Boccaccio). The author discusses the probable causes of the choice made in favor of the Boccaccio version, rather than the expanded version of Petrarch.