The Princeps Senatus is the office of the most senior senator. Seniority is determined in order of precedence by highest offices held, length of time on the senate, and duration of time as a citizen of the Roman Republic. The censors have the power to appoint a senator to this office based on seniority criteria. As in antiquity this office holds great prestige and honour.
Within the Res publica the Princeps Senatus has some additional privileges. They may summon sessions of the senate, add items to the agenda, impose rules of order during senate sessions, and adjourn senate meetings. For ceremonial purposes their person represents the dignity and honour of the senate.