This thesis is a study of the character of the female warrior in English and French epic fantasy based on a corpus made up of leading authors of the genre (Tolkien, M. Z. Bradley, R. Hobb, D. Gemmell) and French authors of award-winning novels (J-L. Del Soccoro, E. Faye, J. Niogret, L. Davoust, P. Beorn). This genre of action and adventure has traditionally been written in the masculine form, but several notable developments warranted an investigation based on a large corpus. If this character can be linked to mythical-historical figures, it has diversified to respond to numerous issues linked to the active and armed female body -masculinised or hyperfeminised-, but also to the relationship of the female warrior to the family, motherhood, and violence, issues that touch on the definition of the female gender. The study questions the objectives of authors who bring a warrior heroine to the forefront and the effects of this choice on gender. It demonstrates that the development of female warrior characters allows novelists to enrich the genre of epic fantasy by expanding its narrative horizons so as to resonate with contemporary societal concerns. By bringing forgotten or underestimated historical figures to the fore and approaching them from new points of view, they offer a counter-history, that of the defeated and/or of women. By imagining plots around subjects that are rarely addressed in this literary genre - motherhood, women's struggle for freedom, matriarchy, etc. - they raise awareness among their readers. By devising plots about subjects not often addressed in this genre of literature - motherhood, women's struggle for freedom, matriarchy, etc. - they make their readers aware of feminist issues and question gender assignments. Oscillating between the renewal of stereotypes and the renewal of gender codes, epic fantasy, literature of escape and entertainment, fully echoes our "primary world", the struggles that involve women and the ideals of gender equality through these "secondary worlds".