The following paper argues that the series of desecrated altars that are found in the Aeneid reflects prior moments of ruptured alliances that have taken place in the epic cycle and Roman history more generally. Vergil has constructed these ruptured alliances along a number of parallel lines that focus on the various means by which the poem constructs ethnic and spatial unification. From the perspective of ethnic amalgamation the infectum foedus of Aeneid 12 raises a number of problems concerning the foundation of Rome and the nature of Roman alliance through time. This problematic alliance that ends the poem, however, moves against the theme of East-West unification in which a central feature of Aeneas’ actions is the reunification of Europe, Asia and Africa through a new system of alliance.