Princeps senatus

The princeps senatus (plural principes senatus) was the first member by precedence of the Roman senate. Although officially out of the cursus honorum and owning no imperium, this office brought enormous prestige to the senator holding it.

The princeps senatus was not a lifetime job. He was chosen by every new pair of censors (that is, every 5 years). Censors could, however, confirm a princeps senatus for a period of another 5 years. He was selected from patrician senators with consular rank, usually former censors. The successful candidate had to be a patrician with an impeccable political record, respected by his fellow senators.

Originally, the position of the princeps was one of honor: he had the privilege of speaking first on the topic presented by the presiding magistrate. This gave the position great dignitas as it allowed the princeps to set the tone of the debate in the Senate. In the late Republic and in the Principate, the office gained the prerogatives of the presiding magistrates and additional powers, namely:

Summoning and adjourning the Senate
Deciding its agenda
Deciding where the session should take place
Imposing order and other rules of the session
Meeting, in the name of the senate, with embassies of foreign countries
Writing, in the name of the senate, letters and dispatches

After the fall of the Roman Republic, the princeps senatus was the Roman Emperor (see also: princeps). However, during the Crisis of the Third Century, some others held the office; the future emperor Valerian held the office in 238, during the reigns of Maximinus Thrax and Gordian I.