Between 1440 and 1550, a genre known as sentimental romance flourished in Spain. Although the genre's works were in many ways varied, they all follow a recognizable model - in particular, a plot pattern that can be described as follows: A young man falls in love with a damsel who, after initially rejecting him, eventually reciprocates his affection. At some point, their mutual love becomes known and outside forces step in to thwart their passion and leave the would-be lovers heartbroken. The last two works of this genre, Processo de cartas de amores and Quexa y aviso contra amor, were written by Juan de Segura and first published in 1548. I have studied and compared the four editions published in the sixteenth century and prepared the first critical edition of both works with the intention of making them accessible to a broader audience of scholars and students. The edition is accompanied by detailed linguistic, historical, and literary notes, including discussions on the use of mythological figures in both texts and references to other literary works that may have influenced the author. I have also prepared a critical apparatus in which I collect all the linguistic variants found in the four editions, and provide additional commentary and context to explain decisions made in my edition, including explanations of the difficulties inherent in the printing process at the time. In the introduction, I provide a comprehensive study of the historical and literary contexts in which the narrations were composed, and a review of what we know about Segura's biography as well as the subjects that have received attention from modern literary scholars. I discuss a remarkable act of self-censorship by the editors of one of the sixteenth century editions, a topic undocumented until now. I also identify important textual sources that Segura employed, such as the poetry of Juan de Mena and Juan del Encina, and the work of Hernán Núñez de Toledo. Finally, I situate Processo de cartas de amores and Quexa y aviso contra amor within the genre of sentimental romance, to show their innovation and to explore their relationship to the byzantine and chivalric genres.