|Millennium:||1st millennium BC|
|Centuries:||2nd century BC – 1st century BC – 1st century|
|Decades:||60s BC 50s BC 40s BC – 30s BC – 20s BC 10s BC 0s BC|
|Years:||39 BC 38 BC 37 BC 36 BC 35 BC 34 BC 33 BC 32 BC 31 BC 30 BC|
|Categories:||Births – Deaths – Architecture|
Establishments – Disestablishments
- Octavian defeats Mark Antony and Cleopatra VII of Egypt at the Battle of Actium (2 September 31 BC). On August 30 BC Octavian captures Alexandria. Marcus Antonius and Cleopatra suicide (kill themselves). Romans kill Cleopatra's son and co-ruler (this means they ruled the country together) Ptolemy XV Caesarion. Egypt becomes part of the Roman Republic and Octavian becomes the ruler of Rome and all Romans. Rome will soon become an Empire not a Republic.
- Herod the Great builds Masada (37–31 BC) as a place to escape to if Jewish people attack him.