This thesis considers the role and presentation of Cú Chulainn in a broad range of texts belonging to the Ulster Cycle. Chapter I offers a general introduction to the thesis. Relevant scholarly theories to date are presented along with an outline of the methodological approaches underpinning this study. The scope of the research in the form of a database of tales is detailed in Chapter II. The textual history of this material is also found therein. This is intended as a quick reference chapter. Chapter III considers the key area of Cú Chulainn’s heroic biography. This encompasses a study of his depiction in a number of tales including Táin Bó Cúailnge. In a bid to provide a well-rounded evaluation of the hero, a number of key thematic elements are addressed in the remaining chapters. Understandably, considerable emphasis is placed upon his function as a warrior. Chapter IV looks at his martial prowess, his ríastrad, his weaponry and his special skills or cleasa. Warrior codes and honour are discussed in Chapter V. Chapter VI moves away from the domain of warfare to examine his physical presentation and his appeal to the opposite sex. His offspring are also considered therein. Cú Chulainn’s parentage and his connection to his homeland, Mag Muirthemne, are appraised in Chapter VII along with an evaluation of his presentation as a saviour-type figure. Finally, Chapter VIII draws together the general research findings with concluding remarks about Cú Chulainn’s role within these sagas.