The dissertation demonstrates how Calderón's plays critique early modern constructions of masculinity. As no historical studies based on gender theory have been made of Golden Age masculinities, the first two chapters, roughly one third of the dissertation, address this lack. Evidence is drawn from various sources, including manuals written specifically to aid the education of young males, the writings of politicians and arbitristas on the needs of Spanish society, journals of those involved in the administration of justice, and the conclusions of modern historians. Chapter one begins by considering the theoretical justification behind the study of masculinities, placing it in the context of feminist scholarship. It then investigates theoretical explanations for the construction of gender difference using theories derived from anthropology. The plurality of gender constructs is acknowledged and explored by an examination of how different constructions of masculinity have developed at different points in history, often remaining in conflict within the same society. Chapter two moves on to consider how the constructions of gender described in chapter one were maintained in sixteenth century Spain. First an examination of conduct manuals demonstrates the tension between beliefs in gender as social construct and as natural essence in the early modern period. It is then shown how society polices gender boundaries by constructing masculinity in opposition to femininity, youth and homosexuality, with examples of how official and unofficial rules and discourse punished deviance. The chapter concludes with an examination of gender and sexuality in the context of the Golden Age popular theatre. The discussion of Calder6n's work begins in chapter three. Following on from conclusions reached in chapter two regarding the relationship between the theatre and society, theories of the male gaze are seen to be particularly relevant to masculinity and are applied to Dario todo y no dar nada. The analysis shows how the play manipulates identification with the male characters on stage, subverting conventional dramatic structures to present a heroine who resists the male gaze that attempts to establish her as a sexual object. Chapter four develops the concept of the gaze, widening its scope to consider the interplay between gender and ethnicity. The chapter examines relations between the individual male and the group, and the objectification of the other, both male and female. In Amar despues de la muerte, the text is seen to subvert traditional ways in which the Spanish male had looked at Morisco men and women. Religion has traditionally been one of the means by which social constructions have been naturalised and thus justified. Chapter five investigates the association between religion and gender, in particular the connections between female sexuality and the Garden of Eden. El ma.gico prodigioso is seen to reverse conventional expectations. Chapter six studies violence to women, particularly rape, and how male collusion in such violence is dramatised in No hay cosa coma ea/far. The play expresses the voice of the female victim often silenced in society. The ambiguous representation of the male protagonist/ villain foregrounds the fact that traditionally such male violence has been condemned in theory but often condoned in practice. The final chapter explores the representation of masculine insecurity in El medico de su honra using object relations theories. The play is seen as an extreme example of the violence and objectification of women discussed in earlier chapters, as well as a consummate representation of the instability of constructions of masculinities. It is thus an appropriate text with which to conclude the dissertation.