Prehistorians working in the Mediterranean have long realised that islands have been central to human mobility from early times. Indeed, the traditional focus on material culture studies, in particular regional and island-group typologies and chronologies, was borne out of the need to understand processes of culture change. Using the concept of the ‘maritory’, this chapter identifies three major cycles of object/human/knowledge mobility that characterise the island worlds of the south-central Mediterranean in the course of the Bronze Age. The social significance of interaction by coastal communities living on either side of a tract of sea is explored.