Examining local politics in three Japanese domains (Yonezawa, Tokushima, and Hirosaki), this book shows how warlords (daimyo) and their samurai adapted the theory and practice of warrior rule to the peacetime challenges of demographic change and rapid economic growth in the mid-Tokugawa period. The author has a dual purpose. The first is to examine the impact of shogunate/domain relations on warlord legitimacy. Although the shogunate had supreme power in foreign and military affairs, it left much of civil law in the hands of warlords. In this civil realm, Japan resembled a federal union (or compound state), with the warlords as semi-independent sovereigns, rather than a unified kingdom with the shogunate as sovereign. The warlords were thus both vassals of the shogun and independent lords. In the process of his analysis, the author puts forward a new theory of warlord legitimacy in order to explain the persistence of their autonomy in civil affairs.