The study of medieval and early modern diplomacy has long been considered one of the most conservative subdisciplines in the field of history. During the last three decades, however, diplomatic history has undergone profound changes. This introductory article shows how these changes were triggered by developments in other disciplines and happened under the influence of the cultural turn. Until recently most general histories of diplomacy were based on the conceptions of Donald Queller and, more particularly, of Garrett Mattingly. Scholars working on medieval and early modern history have applied new international relations theories and moved away from analyses that were strictly oriented towards diplomatic relations between sovereign territorial states. The cultural turn gave rise to a range of innovations in diplomatic history, leading historians to focus on the diplomatic process and its cultural dimensions rather than on the results of diplomatic activity. The special issue for which this article serves as an introduction shows that historians working in the Netherlands have also been influenced by these developments.