TribuneThe Roman office of Tribunes of the People was established in 494 BC, about 15 years after the foundation of the Roman Republic in 509. The plebeians of Rome seceded as a group - left the city entirely - until the patricians agreed to the establishment of an office that would be sacrosanct and have the power to veto (Latin, "I forbid") the action of any magistrate. The plebeians swore that they would kill anyone who harmed a tribune during his term of office. In about 450 the number of tribunes was raised to 10.
Tribunes were required to be plebeians, and until 421 this was was the only office open to them. In the late Republic the patrician politician Clodius arranged for his adoption by a plebeian branch of his family, and successfully ran for the tribunate.
By extension from the technical Roman governmental usage, some modern politicians have been identified as "Tribunes of the People." .
Throughout the Republic and its fall, certain powerful individuals used the tribunes for their personal glory and gain. Clodius and Milo were both tribunes who used violence in the courts and government in order to achieve the needs and requests of Pompey and Caesar. Further more, when the Senate refused to grant Caesar all his requests he turned to the tribunes to grant him all he wanted -- ie. Pompey's veterans lands and him a further governship of Gaul. Again violence was used against those tribunes that prevented their quest for glory.