This volume offers a distinct interpretation of the genesis of one of the most fascinating genres of Spanish medieval literature, the fifteenth-century Spanish sentimental novel. This work examines the seminal importance of Historia de duobus amantibus, a work by Eneas Silvio Piccolomini, later known as Pope Pius II, in the development of the novel genre in Spain which originates with the acclaimed piece by Juan Rodríguez del Padrón: Siervo libre de amor.