This article makes the case for recovering women’s roles from the forgotten corners of diplomatic history, and for considering the consequences of the gap between feminist and non-feminist research. It shows how ignorance of the gendered nature of diplomatic norms and practices impacts our understanding of diplomatic history, and how specific biographies are hampered by gender blindness in particular. Using the history of Margaret van Kleffens and Dutch World War II diplomacy as an example, the article demonstrates how historians’ continued neglect of the role of women and gender norms has influenced representations of twentieth-century diplomacy. To dismiss the history of gender and of women as by definition irrelevant to the actions of states and of male statespersons is not simply part of a self-appointed focus on the political at the expense of the personal; rather, it omits much of the political history too, reproducing stereotypes and resulting in a skewed understanding of diplomatic history and foreign policy decisions. The article argues that both historians and feminist scholars need to historicize gender in order to recognize women’s roles in diplomacy, and so gain a better understanding of the history of international politics as a whole.