This book considers the role played by Denmark’s King Frederik II (1559-88) in the international diplomacy of the ‘age of religious wars’. As Europe’s leading Lutheran sovereign, Frederik commanded great influence; his conviction that an international Catholic ‘conspiracy’ threatened to destroy Protestantism led him to work towards the creation of a Protestant alliance that included both Calvinist and Lutheran states. Lockhart examines the role of religion in Frederik’s foreign policy, the motivations behind the king’s alliance-building projects, and the reasons behind the ultimate failure of Frederik’s policies. This volume will be of interest to students of early modern diplomacy, sixteenth-century Protestantism, and the Scandinavian monarchies in the early modern period.