It is generally recognized that Rome of the early Republic offers a good example of the correlation between military and political organization. The ordering of the Roman citizenry in centuries, classes and age-groups was in origin and essence a military system. The Comitia Centuriata was the exercitus urbanus—the army on parade in the Field of Mars.But by the third century B.C. the Roman army and the centuriate assembly were manifestly two different systems, even if vestiges of their interconnection lingered on. The process whereby this differentiation had come about is, unfortunately, not so clear. The traditional accounts of early Roman history generally failed to devote much attention to questions of that order. Yet the effort to tackle and, if possible, solve this complex of problems can hardly be evaded. The answers given, or assumed, by modern historians are bound to determine how the whole history of early Rome is interpreted and represented.