In the Later Roman Empire (AD 300-650), power seems to manifest itself mostly through legislation, bureaucracy, and an increasingly distant emperor. This book focuses instead on personal interaction as crucial to the exercise of power. It studies four social practices (petitions, parrhesia, intercession, and collective action) to show how they are much more dynamic than often assumed. These practices were guided by strong expectations of justice, which constrained the actions of superiors. They therefore allowed the socially inferior to develop strategies of conduct that could force the hand of the superior and, in extreme cases, lead to overturning hierarchical relations. Building on the analysis of these specific forms of interaction, the book argues for an understanding of late antique power rooted in the character and virtue of those invested with it.