The Senate grants Octavian the title Augustus; he becomes the first Roman emperor, inaugurating the Pax Romana.
Date given in the Julian calendar.
Octavian's fleet defeats Mark Antony and Cleopatra, clearing his path to supreme power in Rome.
Julius Caesar is stabbed to death in Rome by senators including Brutus and Cassius on the Ides of March.
Julius Caesar leads his army across the Rubicon into Italy in defiance of the Senate, starting a civil war with Pompey.
Julius Caesar defeats the Gallic leader Vercingetorix, effectively completing the Roman conquest of Gaul.
Germanic tribes led by Arminius annihilate three Roman legions, halting Roman expansion beyond the Rhine.
Augustus, the first Roman emperor, dies and is succeeded by his adopted son Tiberius.