This book explores the international ambitions and foreign policies pursued by Imperial Germany’s federal monarchs. When the German Empire was founded, more than twenty German kings, grand dukes, dukes, and princes—formerly independent rulers—saw their realms become integrated into a federal state with a German army, a German parliament, and a German Foreign Office. At the helm stood a German Emperor who, in his position as Supreme War Lord, was entitled to declare war and to make peace on behalf of the whole country. On the other hand, the Reich was a federation and not a consolidated, unified state: by law, its twenty-five constituent states retained their sovereignty in internal matters and, to a certain extent, foreign affairs.

The Kaiser’s Hidden Diplomats argues that both individually and collectively, these 'semi-sovereign' monarchs helped stabilize relations between European powers for almost half a century. During the decades before the First World War, decision-makers in Europe and beyond regarded these rulers as a diplomatic wildcard, jokers in the diplomats' deck that could be played when other cards were unavailable. This study also investigates the uniqueness of these monarchs and states compared to other semi-sovereign entities in the Age of Empire.

David Korsuize is a Lecturer in the History of International Relations, Utrecht University, The Netherlands.