This is the first full-scale study in English of the reign of Frederick William IV, King of Prussia from 1840 to 1861, and arguably the most important German monarch in the century between the death of Frederick the Great and the accession of William II. Although Frederick William has long been criticized as a Romantic reactionary who was utterly out of touch with his times, this study reaches different conclusions, arguing that he was in fact a modern and in many ways, 'successful' monarch.The book is not a biography in the traditional sense. Rather, it focuses on the structures, institutions and transformations of the monarchial system in Prussia during a time of revolutionary change. It thus represents a contribution to our understanding of the structures of the nineteenth-century European state, and the strategies by which conservative elites were able to adjust themselves to new circumstances.