a. It must be recollected that the only existing political organization was that of the Patricians into 3 tribes, 30 curiæ, and 300 gentes; but Servius now divided the whole Roman territory into Thirty Tribes, and, as this division was simply local, these tribes contained Plebeians as well as Patricians. But, though the institution of the Thirty Tribes gave the Plebeians a political organization, it conferred upon them no political power, nor any right to take part in the elections, or in the management of public affairs. At a later time the tribes assembled in the forum for the transaction of business, and were hence called Comitia Tributa. The Patricians were then excluded from this assembly, which was summoned by the Tribunes of the Plebs, and was entirely Plebeian.

b. The means by which Servius gave the Plebeians a share in the government was by establishing a new Popular Assembly, in which Patricians and Plebeians alike voted. It was so arranged that the wealthiest persons, whether Patricians or Plebeians, possessed the chief power. In order to ascertain the property of each citizen, Servius instituted the Census, which was a register of Roman citizens and their property. All Roman citizens possessing property to the amount of 12,500 asses and upward[7] were divided into five great Classes. The First Class contained the richest citizens, the Second Class the next in point of wealth, and so on. The whole arrangement was of a military character. Each of the five Classes was divided into a certain number of Centuries or Companies, half of which consisted of Seniores from the age of 46 to 60, and half of Juniores from the age of 17 to 45. All the Classes had to provide their own arms and armor, but the expense of the equipment was in proportion to the wealth of each Class. The Five Classes formed the infantry. To these five Classes were added two centuries of smiths and carpenters, and two of trumpeters and horn-blowers. These four centuries voted with the Classes. Those persons whose property did not amount to 12,500 asses were not included in the Classes, and formed a single century.

At the head of the Classes were the Equites or cavalry. These consisted of eighteen centuries, six being the old patrician Equites, as founded by Romulus and augmented by Tarquinius Priscus, and the other twelve being chosen from the chief plebeian families.[8]

The Centuries formed the new National Assembly. They mustered as an army in the Campus Martius, or the Field of Mars, on the banks of the Tiber, outside the city. They voted by Centuries, and were hence called the Comitia Centuriata. Each Century counted as one vote, but did not consist of the same number of men. On the contrary, in order to give the preponderance to wealth, the first or richest class contained a far greater number of Centuries than any of the other classes (as will be seen from the table below), although they must at the same time have included a much smaller number of men. The Equites and First Class alone amounted to 100 Centuries, or more than half of the total number; so that, if they agreed to vote the same way, they possessed at once an absolute majority. An advantage was also given to age; for the Seniores, though possessing an equal number of votes, must of course have been very inferior in number to the Juniores.

Servius made the Comitia Centuriata the sovereign assembly of the nation; and he accordingly transferred to it from the Comitia Curiata the right of electing kings and the higher magistrates, of enacting and repealing laws, and of deciding in cases of appeal from the sentence of a judge. But he did not dare to abolish the old Patrician assembly, and was even obliged to enact that no vote of the Comitia Centuriata should be valid till it had received the sanction of the Comitia Curiata.

Thus, in consequence of the legislation, we shall find that Rome subsequently possessed three sovereign assemblies: 1. The Comitia Centuriata, consisting of both Patricians and Plebeians, and voting according to Centuries; 2. The Comitia Curiata, consisting exclusively of Patricians, and voting according to Curiæ; 3. The Comitia Tributa, exclusively of Plebeians, and voting according to Tribes.

II. The second great work of Servius was the extension of the Pomœrium, or hallowed boundary of the city, and the completion of the city by incorporating with it the Quirinal, Viminal, and Esquiline Hills.[9] He surrounded the whole with a stone wall, called after him the wall of Servius Tullius; and from the Porta Collina to the Esquiline Gate, where the hills sloped gently to the plain, he constructed a gigantic mound nearly a mile in length, and a moat 100 feet in breadth and 30 in depth, from which the earth of the mound was dug. Rome thus acquired a circumference of five miles, and this continued to be the legal extent of the city till the time of the emperors, although suburbs were added to it.

III. An important alliance with the Latins, by which Rome and the cities of Latium became the members of one great league, was one of the great events which distinguished the reign of Servius.