Comitia, the public assemblies of the Roman people for the transaction of important political business. There were three different kinds of comitia, corresponding to the three great divisions of the Romans: the comitia curiata, the comitia centuriata, and the comitia tributa. The comitia curiata, or assemblies of the curia, were the original assemblies said to have been instituted by Romulus, and managed all the great concerns of state prior to the establishment of the comitia centuriata. They elected the kings and other chief magistrates, enacted and abrogated laws, and judged capital offenders. After the institution of the comitia centuriata, their prerogatives were gradually abridged, till almost all the great powers which they once exercised were wrested from them, and hardly any remained with them, save those minor ones which they had possessed from the beginning, in common with the higher rights annulled. The comitia curiata were originally called together by the kings, but in republican times generally by some great secular or sacerdotal magistrate. They were composed of those Roman citizens who were members of the curiae, dwelt within the pomcerium, and conformed to the customs and rights of their respective wards.

The meetings were not held periodically, but as often as there was business to transact. When the members were assembled, and the omens propitious, the rogatio, or matter to be considered, was read, and then each curia, after deciding apart on the question, gave its vote, and the votes of the majority of the curiae determined the fate of the measure, or, if it was a case of election, that of the candidates. These assemblies were held in that part of the forum called the comi-tium. The comitia centuriata were instituted by Servius Tullius, the sixth king of Rome, with the view apparently of uniting in one body the different sections of the Roman people. Having compelled every man to give in an accurate account of his property, he divided the citizens into six classes, according to their wealth, which he subdivided, according to Dionysius, into 193 centuries. Of these centuries he composed the comitia centuriata, which were held in the Campus Martius, for the election of consuls, censors, and praetors, for the trial of persons accused of what was termed crimen perduellionis, or treason, and for the confirmation or rejection of such laws as might be submitted to their consideration. The most usual time of meeting was about the end of July or beginning of August in each year.

When the centuries were assembled, they cast lots for priority of suffrage, and the century to which the lot fell voted first, and was styled centuria prmrogativa. All the others voted in the order of their classes, and as they were summoned, and were thence termed jure vocatce. The presiding magistrate having ordered the prerogative century to be called out to give their suffrages, its members came forward and entered an enclosed space named septum or ovile, where, if it was a case of election, every man received as many tablets as there were candidates, every tablet having inscribed on it the initial letters of one candidate's name. The septa contained numerous large ballot boxes, and into one of these the voter cast that tablet which bore the initials of the name of the candidate whom he favored. If, however, it was a question of the confirmation or rejection of a law, only two tablets were handed to each voter, on one of which were written U. R., the initial letters of Uti rogas, "As thou desirest," and on the other A., the first letter of Antiquo, "For the old," i. e., the old law (against the new). At each ballot box were stationed certain officers called custodes, who took the tablets of every century out of the ballot box, and numbered them by putting a puncture in another tablet for every one deposited.

Before the introduction of the ballot system, however, when every citizen voted viva voce, an officer called a rogator, stationed at the entrance of the septum, asked each individual for his vote. In the election of magistrates, or the confirmation or rejection of laws, equality of suffrages nullified the vote of the century; but in juridical cases equality of suffrages was deemed an acquittal of the accused. The comitia tributa, or assemblies of the tribes, were not established till 491 B. C. They were sometimes presided over by the tribunes of the people, sometimes by the consuls or praetors, and were summoned for the election of tribunes, aediles, quaestors, and other inferior magistrates, for the trial of minor criminals, and for the enactment of special and general statutes. Their place of meeting was not fixed; occasionally they were convened in the Campus Martius, occasionally in the forum, and at times in the circus Flamin-ius. These were the democratic comitia. Their laws were termed plebiscita, or decrees of the plebs, and, unlike the other comitia, they could be called together without the sanction of the senate.

Besides these great assemblies, there were in the later ages of the republic lesser comitia, termed comitia calata, which were held for the election of priests and the regulation of testamentary matters, and in which the people acted only as witnesses.