The aim of my doctoral project is to elucidate the strategies employed to convey feminine subjectivity in the 13th century Tristan en Prose and examine the relationship between these depictions of subjectivity and the apparent virtue of the two main female characters: the infamous adulteresses, Guinevere and Iseut. The Tristan en Prose offers a unique opportunity for analysis of the adulteresses as it fully integrates the Tristan story into the Arthurian world, thus placing Guinevere and Iseut in the same text. By subjectivity, I refer to the construction of a fictional consciousness through the presentation of speech, thoughts, and actions. The study will consider the impact of three contrasting influences on feminine virtue in the Tristan en Prose: conceptions of ennobling and passionate love, Christian views on love and marriage, and the 'Celtic logic' of the matière de Bretagne.