Magistrates were executive officers of the Roman state, most of them both military and civilian leaders, whose offices were interwoven inseparably with public religious duties. The Greek historian, Polybius highly recommended this system:
"There can surely be nobody so petty or so apathetic in his outlook that he has no desire to discover by what means and under what system of government the Romans succeeded in less than fifty-five years in bringing under their rule almost the whole of the inhabited world". (Polybius 1.1, trans. Scott-Kilvert)
Ordinary and extraordinary magistracies
The ordinary magistracies (magistratus ordinarii) were those which were filled every year by regular elections. Roman magistracies can be classified in several ways, the two most reasonable classification is the one according to their power and political rank (potestas), the other is the classification according to their "sanctity" (auctoritas). The ordinary magistracies in decreasing order of potestas were:
Although the tribunatus plebis was not technically classified as a magistracy, in practice it was one of the ordinary magistracies.
Though the censura is considered an ordinary magistracy, it was filled only in every five years (in some cases not even then), and their term of office lasted 18 months, therefore it was between the ordinany and the extraordinary magistracies.
The extraordinary magistracies (magistratus extraordinarii) were those which were filled only when they were needed. They were the:
- Magistratus Equitum
- Triumviratus rei publicae constituendae
- Decemviratus legibus scribundis
Higher and lower magistracies
The higher magistracies (magistratus maiores) were those which were most senior in rank. They were elected by the highest of the popular assemblies, the comitia centuriata. The higher magistracies, in decreasing order of potestas, were the:
The higher magistracies can also be classified after the degree of auctoritas they have. The higher magistracies, in decreasing order of auctoritas, were the:
The rest were lower magistracies (magistratus minores):
The tribunatus plebis is not technically classified as a magistracy, and it would not be correct to regard it as either a higher or a lower magistracy.
The extraordinary magistracies are not classified as either higher or lower magistracies.
Magistracies with and without imperium
Imperium was the highest form of executive power in the ancient Roman republic. The magistratus cum imperio, those magistracies which carried not only potestas but also imperium, in decreasing order of imperium, were the:
The dictator had an extraordinary imperium which exceeded the power of any of the ordinary magistrates, and could never be held legally responsible for any action during his time in office for any reason.
The power of the interrex is hard to classify. Logically it ought to be imperium, because the constitutional duty of the interrex was to preside over the election of the consules, and this required the convention of the comitia centuriata: only a magistrate with imperium could convene the Comitia Centuriata. However, strong custom prevented the interrex from exercising the full range of imperium.
Magistracies without imperium mostly had the lesser power of potestas:
Curule and non-curule magistracies
The curule magistracies (magistratus curules) were those whose holders were entitled by virtue of their office to sit on the curule chair (Latin sella curulis), to wear the toga praetexta and being proceeded by lictores and whose descendants were regarded as nobiles. They were the:
The non-curule magistrates were the:
The tribunatus plebis, not technically a magistracy at all, was not a curule office.