This chapter outlines the concept of sovereignty in Francisco de Vitoria’s theological discourse. His thoughts on the matter emerge within the context of a growing imperial ethos spearheaded by both Emperor and Pope in their claims over the communities of the New World in the sixteenth century. As against the postulates set forth by both royal and ecclesiastical power, Vitoria’s lectures drew out a framework that served to establish the sovereign status of those communities on theological and juridical grounds. This brief overview addresses Vitoria’s line of reasoning in this respect and argues that his lectures on civil power, the laws of war and the Indies established an iusnaturalistic conception of sovereignty, which placed significant limits on empire and the use of force among states and communities.