Tribune of the plebs
Tribune of the plebs, tribune of the people or plebeian tribune (Latin: tribunus plebis) was the first office of the Roman state that was open to the plebeians, and was, throughout the history of the Republic, the most important check on the power of the Roman Senate and magistrates. These tribunes had the power to convene and preside over the Concilium Plebis (people's assembly); to summon the senate; to propose legislation; and to intervene on behalf of plebeians in legal matters; but the most significant power was to veto the actions of the consuls and other magistrates, thus protecting the interests of the plebeians as a class.