Originally intended as assistants to the tribunes, they exercised certain police functions, were empowered to inflict fines and managed the plebeian and Roman games.
13 introduced (as one of the tribunes) a bill proposing that all debts should be cancelled.
They were created in the same year as the tribunes of the people (494 B.C.), their persons were sacrosanct or inviolable, and (at least after 471) they were elected at the Comitia Tributa out of the plebeians alone.
One of the tribunes even threatened to put his veto on the bill, which was withdrawn before the voting took place.
Although he permitted the existence of a board of Nine Men to act as " tribunes " for the people it was originally composed of his selections from eighteen persons chosen at a popular election, and annually thereafter the places of six retiring members were filled by his selections from twelve persons nominated by the board.