Tribune: Roman official whose task it was to protect the people against oppression.
The Tribunes were the most powerful plebeians. Their primary purpose was to serve the will of the plebeians. They were considered the embodiment of all plebeians, and therefore were sacrosanct. All of the powers of the Tribune derived from this sacrosanctity. One obvious consequence of this sacrosanctity was the fact that it was considered a capital offense to harm a Tribune, to disregard his veto, or to interfere with or obstruct the tribune.
Another obvious consequence was the Tribunes also had the ability to rescue any other plebeian from the actions of another magistrate. Tribunes had the authority to enforce the right of provocatio. This was a theoretical guarantee that a plebeian could not be executed without a trial. If a plebeian was in trouble, he could yell “provoco ad populum”, and a Tribune would be able to prevent the governmental action against that plebeian. The lex Porcia of Cato later expanded the provocatio protection to include protection against flogging. In 300 BC, the lex Valeria was passed, which strengthened provocatio. The result was that any action taken in spite of a valid provocatio was on its face illegal.
Besides provocatio, another facet of a tribune’s sacrosanctity was auxilium (help). This was a protection for plebeians, which could be requested by a formal appeal. To help ensure that this was available, a tribune’s house had to be open to the public day or night. During the day, the tribunes had a station at the Basilica Porcia. This was the only major tribunician power that survived well into the Empire.
Tribunes could use their sacrosanctity to order the use of capital punishment against any person who interfered with their duties. However, the sacrosanctity of a Tribune (and thus all of the tribunician powers), were only in effect as long as the Tribune was within the city of Rome (or no more than one mile (1.6 km) outside of the city’s gates).
Tribunes presided over the Plebeian Council. Therefore, they had the ability to open and close sessions, and call the council to order. They also had the ability to introduce (or not introduce) bills before the council. Since members of the assemblies could not introduce bills for consideration, the Tribune was usually the only person who would introduce such bills. In addition, each Tribune was assigned two aediles as his subordinates.
Tribunes used their sacrosanctity as protection when physically manhandling an individual, such as when arresting someone. They also used it to prevent being interrupted during a speech before an assembly or the Senate. Their veto powers functioned through a similar mechanism. During the early republic, tribunes could only sit near the senate door. Their veto power would be exercised by blocking (or threatening to block) the door, and thus preventing any senator from leaving the building. Their sacrosanctitiy prevented a senator from using force to remove the tribune from the door. By the early 3rd century BC, tribunes were allowed to sit with the senators, and even participate in debate. With this change, the veto power shifted from one of physical obstruction to one of senate procedure.
According to Polybius, Tribunes could also prevent the senate from convening. The origin of this power may have been their ability to use their sacrosanctity to physically block the senate door. This would have prevented any senators from entering the building.
The Tribune could also veto any action of any legislative assembly. However, such a veto would have to take place before a vote was called. While tribunes often vetoed legislation, they only rarely (if ever) issued vetoes in electoral or judicial matters. Despite the fact that a tribune had the right to veto any act of an assembly, the nature of such a veto ran counter to the role of the tribune (to advocate on behalf of the people). And as such, often a tribune’s veto over a legislative assembly was withdrawn after protests from the members of that assembly.
On a couple of rare occasions (such as during the tribunate of Tiberius Gracchus), a tribune might use a form of blanket obstruction. This would involve vetoing all governmental functions, and placing a seal on the treasury.