While common law actions for breach of promise of marriage originated in the mid-seventeenth century, it was not until the ‘long nineteenth century’ that they saw their rise to prominence and their subsequent fall from favour. This monograph ties the story of the action's rise and fall between 1800 and 1940 to changes in the prevalent conception of woman, her ideal role in society, sexual relations, and the family, arguing that the idiosyncratic nineteenth-century breach-of-promise suit (a luxuriant blend of both contract and tort) and Victorian notions of ideal femininity were uneasily and fatally, but nonetheless inextricably, entwined. It classifies the ninteenth-century breach-of-promise action as a ‘codification’ of the contemporaneous ideal of true womanhood and explores the longer-term implications of this infusion of mythologized femininity for the law, in particular for the position of plaintiffs. Surveying three consecutive time periods – the early nineteenth century, the high Victorian, and the post-Victorian periods – and adopting an interdisciplinary approach that combines the perspectives of legal history, social history, and literary analysis, it argues that the feminizing process, by shaping a cause of action in accordance with an ideal at odds with the very notion of women going to law, imported a fatal structural inconsistency that at first remained obscured, but ultimately vulgarized and undid the cause of action. Alongside more than two hundred and fifty real-life breach-of-promise cases, the book examines literary and cinematic renditions of the breach-of-promise theme, by artists ranging from Charles Dickens to P. G. Wodehouse, in order to expose the subtle yet unmistakable ways in which what happened (and what changed) in the breach-of-promise courtroom influenced the changing representation of the breach-of-promise plaintiff in nineteenth- and early twentieth-century literature and film.