Heraldry was an omnipresent feature of medieval and early modern state rooms and thus a crucial element to the visual programme in palaces, castles, residences and town halls. In spite of its massive presence, its function and significance have hardly been investigated and its specific contribution to these spaces has often been neglected. This collection of papers shows to what extent coats of arms contributed to or even shaped the communication of these rooms and demonstrates how heraldic programmes provide a better understanding of the strategies of self-representation and communication of their commissioners and users. In so doing, the authors offer first guidelines on how to approach these rich and complex sources and how to use them to better comprehend medieval and early modern state rooms and their cultural and political settings.