Counterfactualist approaches to the past (e.g., “What if Germany had won WWII?”) are common, if commonly derided, in various subdisciplines of history, and increasingly prevalent in popular film and narrative fiction. Literary criticism, however, has only begun to consider the phenomenon (and medieval studies not at all), despite counterfactual history’s potential for opening up the textual past in new ways. This essay risks the censure of “responsible” historians by asking what implications the interwoven topics of genre prescription, gender ideology, and historical contingency may have for the practice of counterfactual literary history in a specifically medieval context. My case study, drawn from the trilingual miscellany Harley 2253 (c.1330–40), is a scandalously obscure Anglo-Norman bourde (jest, tale) known as Gilote et Johane: a fast-moving, genre-bending hybrid in which two young women debate sexual mores, take lovers, outwit fathers, shout down clergy, advise passing wives, preach their audacious “lesson” to churchfuls of femmes, and finally burst forth from Winchester to spread their mobile erotic doctrine “across all England and Ireland.” As our narrator frames it, the tale is designed to provoke outrage and redoubled vigilance; however, Gilote et Johane’s imagination of an alternative social future enables other, less deterministically “medieval” species of response. Taking seriously the radical counterfactual vision presented by this rollicking “cautionary tale” allows us to reconsider the place of a forgotten poem within a famous manuscript, and within Anglo-Norman and canonical English literary history.