Federal principles do not encourage the dominance of a single locus of power. This is regarded as one of the federal glues that maintain a healthy equilibrium in a federation. By focusing on Brussels and Addis Ababa—the capitals of Belgium and European Union, and Ethiopia and African Union, respectively—this article examines the governances of contested federal capital cities that transcend national politics. The article uses “contested conditions”—historical and contemporary intranational and supranational rivalries and cooperation—to argue that rather than diffusing powers to promote alternative capitals, federalism appears to have enhanced competition over the existing “primate” capital cities.