This dissertation explores references to islands in 13th and 14th century Iberian literature in a corpus of encyclopedias, travel books and chivalry novels from 1223 through 1396. I explore how island geography became part of the Medieval imago mundi. Many Medieval readers were interested in these faraway lands where, they believed, monstrous races flourished, sea monsters lurked, and Paradise awaited to be rediscovered. The physical and human geography featured in these narratives, gave birth to an imaginary, utopian, exotic, extravagant, and mysterious concept of “islandness” located in idyllic places to be interpreted as cognitive maps of the social, politic and economic conventions of the era. The purpose of this dissertation is to contribute with a new approach to Medieval Island Studies by means of a rhetorical analysis in geography through tropes (metaphor, synecdoche, metonym and irony) and fiction modes (romance, tragedy and comedy). This proposal assumes that the author-narrator is a self-aware geographer willing to satiate the desires and prejudices of its audience by constructing an attractive narrative that may stimulate a longing for this unattainable island world.