133 BC

By place

Roman Republic

• Lucius Calpurnius Piso Frugi, as consul, is sent against the slaves in Italy. Gaius Marius serves under Publius Cornelius Scipio Aemilianus at Numantia.
• Scipio Aemilianus captures Numantia, after a siege of eight months, suffering famine and pestilence. The remnant population of 4,000 citizens, surrender and set their city on fire. Thus ends the Numantine War.
• Tiberius Sempronius Gracchus, is elected tribune of the people. He attempts to pass a law to redistribute the public land to benefit small landowners. Opposed by wealthier factions in the Roman Senate, he is killed by a group of Senators and their followers that same year.
• The Kingdom of Pergamum is deeded to Rome, Aristonicus starts a rebellion against this.

  China

• June - A large army of the Han Dynasty, under commanders such as Li Guang, attempts to ambush the Xiongnu leader in the Battle of Mayi. The plot fails, and the battle is determined a draw.