Queens, be they consorts, dowagers or regents, often played pivotal roles in the lives of medieval and early modern kingdoms. As women who often married across geographical, political and, sometimes, religious borders, they were ideally placed to serve as diplomats and ambassadors, whether directly as agents or indirectly as transmitters of cultural practices, values and ideas. This introduction celebrates the position which queens occupied at the heart of international and transnational affairs in the premodern era. It argues that queens were figures who enjoyed meaningful public authority. Their ceremonial actions were imbued with significance, and their deliberate and considered interventions in court politics, and in the wider affairs o...