If woman was already considered a baser being inmedieval English literary culture, then what explainsthe monstrous women--part-animal, ormagically-empowered--who function as typical romanceheroines? If the monstrous women simply dramatize theconventions of medieval misogyny, then why do so manyof them found dynasties, establish empires, and fillthe royal seats across Europe with their offspring? A closer look at the figures of Constance, Medea, andMelusine in 14th, 15th, and early 16th-centuryEnglish narratives reveals how metaphorical femalemonstrosity functions as a critical lens that allowsauthors, and audiences, to reflect on and re-examinemisogynistic conventions, patriarchal authority, andthe romance formula itself. Arguing that the MiddleEnglish romance constructs new possibilities forfiction, this study uses recent scholarship onmonster theory and medieval women to theorize thepresence of these monstrous women in medievalromance, discovering how they trace the formulationof a distinct gender ideology and expose the flaws ofa literary rhetoric that, in defining the female asOther to the normative male, makes women into monsters.