The Ten Commandments (hereafter Decalogue) declare concise yet comprehensive human duties towards God and between humans. After outlining the Decalogue’s variable medieval use, this chapter deploys its twofold structure to consider Reformation-era interpretations of its commands regarding worship (the first table) and society (the second table). Between these, the role of the Decalogue in Reformation discourses about salvation (the uses of the law) is discussed. Reformation legacies are then outlined through comparison between these early and late modern treatments of the Decalogue. It is argued that the Protestant reformers revisited and reshaped problematic aspects of medieval faith and practice by means of the Decalogue, and that an insistent biblicism is key to making sense of their impact. The Protestant Reformation(s) enabled the Decalogue’s prominence, and in turn its pervasive influence, in modernity.