This dissertation aims to depict the daily life of early seventeenth-century common soldiers in as much detail as possible. It is based on intensive statistical study of common soldiers in Electoral Saxony during the Thirty Years War, through which I both analyze the demographics of soldiers' backgrounds and discuss military wages in depth. Drawing on microhistory and anthropology, I also follow the career of a single regiment, headed by Wolfgang von Mansfeld (1575--1638), from mustering-in in 1625 to dissolution in 1627. This regiment was made up largely of people from Saxony but it fought in Italy on behalf of the King of Spain, demonstrating the global, transnational nature of early-modern warfare. My findings upend several assumptions about early seventeenth-century soldiers and war. Contrary to the Military Revolution thesis, soldiers do not appear to have become more disciplined during this period, nor was drill particularly important to their daily lives. Common soldiers also took an active role in military justice.