Tribunes were elected officials in ancient Rome who represented the interests of the common people, known as the plebeians. They had the power to veto decisions made by the Senate and other magistrates, ensuring that the rights of the lower classes were protected. This role was established in the 5th century BCE and became a crucial part of the Roman political system. The position of tribune was significant because it allowed ordinary citizens to have a voice in government. Tribunes could also propose legislation and were considered sacrosanct, meaning that harming them was a serious offense. This helped to maintain their authority and influence in Roman society.