- March 18 - The Roman Senate annuls Tiberius' will and proclaims Caligula Roman Emperor.
- Caligula's attempt to have himself deified creates friction between himself and the Senate
- An earthquake destroys Antioch.
- Saint Peter founds the Syrian Orthodox Church. (traditional date)
- Probable year of the conversion of the Pharisee Saul of Tarsus to Christianity after a vision. After 39 he is recognised as Paul of Tarsus.
- March 16 - Tiberius, Roman Emperor, strangled by Macro, Praetorian Prefect.
- May 1 - Antonia Minor, daughter of Mark Antony and Octavia Minor; grandmother of Caligula.