After the foundation of Rome, the newborn republic, that is, the army of its founder, composed of Albans, Sabines and foreigners, was divided into three classes, which, from this division, took the name of “tribes.” Each of these tribes was subdivided into ten curiae, and each curia into decuriae , headed by leaders called curiones and decuriones .

Besides this, out of each tribe was taken a body of one hundred Equites or Knights, called a “century,” which shows that these divisions, being unnecessary in a town, were at first merely military. But an instinct for greatness seems to have led the little township of Rome to provide itself in advance with a political system suitable for the capital of the world.