Year 66 BC was a year of the pre-Julian calendar.

Events

By place

Rome

• Consuls: Manius Aemilius Lepidus and Lucius Volcatius Tullus.
• Catiline accused of conspiring against the Roman Republic with Autronius and the younger Sulla (also in 63 during the Consulship of Cicero)
• The alliance between Mithridates VI of Pontus and Tigranes II of Armenia is broken.
• Battle of the Lycus — Pompey the Great decisively defeats Mithridates VI, effectively ending the Third Mithridatic War.
• Gaius Antonius elected Roman Praetor.
• The lex Manilia, supported by Cicero gives Pompey command over all of Asia.
• Cicero becomes praetor of Sicily.

Births

Deaths

• Licinius Macer, Roman annalist