The purpose of this thesis is to study the role of women in medieval Spanish literature. My main concern is to provide a comprehensive portrayal of assertive women; that is to say, to describe the actions and to interpret the discourse of females who empower themselves and become the dominant participants in the development of the works' plots. This thesis has three chapters, in which I discuss the role of the female characters from the following genres: the Epic, the Ballads, and the Sentimental Romances. Each chapter is subdivided into three parts: a. The characterization of women in each work is addressed separately; b. The female characters are categorized into specific groups, to provide a descriptive list of prototypes for the different genres; c. The development of a specific topic in the selected genres (i.e. 'Heroines and Villainesses in the Epic', 'Pre-marital Sex in the Ballads', and 'The Defence of Virtuous Women in the Sentimental Romances') is traced and analysed. The generic diversity and the vast chronological span of the works studied allowed for a variety of critical approaches. I do not confine myself to a feminist analysis of the works. I rely heavily on textual interpretation of the characterization of these women, and use a wide range of studies by other scholars to support my hypotheses. Besides the literary criticism, I rely also on a number of historical works which describe the role of women in the Middle Ages. This thesis should confirm the importance of studying the role of women during the Middle Ages, in literature as well as in life. We must allow medieval women to speak if we wish for a wider and better-balanced understanding of the literature of the Middle Ages. I attach as supplementary material offprints of 'Fiometa's Suicide in Grimalte y Gradissa', Journal of Hispanic Research, 1 (1992-93), 345-48, and 'Back to the Text: Another Look at Juan Rodriguez del Padron's Siervo libre de amor', Romanische Forschungen, 106 (1994), 48-60.