Critical and post-colonial scholars have argued that a more complete account of sovereignty necessitates an exploration of the colonial experiences through which Western civilised identity was forged. But the way these ‘distant’ encounters were used in (and interacted with) the process of claiming sovereignty domestically has received less attention. This is surprising as critical scholars have revealed the existence of strong similarities between the domestic and international constructions of sovereignty (and in particular the necessary performance of a savage Other) and have emphasised how sovereignty transcends the domestic/international frontier and provides a crucial link between the two. As a response, this article develops an analysis of the construction of sovereignty that combines both the domestic and international colonial frontiers on which ‘civilised’ sovereignty relies. I use a large set of primary archives about France in the sixteenth century in order to explore how sovereignty depends on unstable colonial frontiers, that is, differentiations between the civilised and the savage, that are constantly contested and re-established. Combining the domestic and international colonial frontiers reveals how they interact and are used in order to reinforce the civilised identity of the Western ruler.