131 BCCenturies: 3rd century BC - 2nd century BC - 1st century BC
- Aristonicus of Pergamon leads an uprising against Rome, and consul Publius Licinius Crassus Mucianius is killed in the fighting.
- The Roman censor Quintus Metellus Macedonicus attempts to remove the tribune Gaius Atinius Labeo Macerio from the Senate, the angry Atinius drags him to be thrown off the Tarpeian Rock, and Metellus is only saved by the intervention of other senators.
- The tribune Gaius Papirius Carbo passes a measure allowing the use of secret ballots in legislative assemblies.
- For the first time in Roman history, both censors are plebeians (Metellus and Quintus Pompeius).