Migration controls are more and more transforming borders. In this regard, this paper is a border case study focusing on the Strait of Sicily. It analyzes the border regime between Italy and its North African neighboring countries Tunisia and Libya from the point of view of the transformations of territorial borders in space and time. It provides an inventory of border control measures and instruments, and analyzes the way they actually work. The evolution of policies and practices of migration controls results in transformations of territorial borders not only in terms of their location (inward and outward flexibilization of the border) but also in terms of their shape (from boundary lines to border zones or points) and operational modalities (from fixity in space and continuity in time to mobility and intermittency). Border transformations are analyzed before the background of Ratzel's idea of Grenzsaum, that is of a borderland both in the sense of a border strip straddling two bounded territories or lying on just one side of a territorial linear border, and in the sense of a buffer zone lying between two territories. © 2014 © 2014 Association for Borderlands Studies.