- 509 BC – According to Roman tradition, the Temple of Jupiter Optimus Maximus (depicted), the most important temple in ancient Rome, was dedicated.
- 1567 – The siege of Inabayama Castle, the final battle in Oda Nobunaga's campaign to conquer Mino Province, began; it culminated in a decisive victory for Nobunaga.
- 1848 – An explosion drove an iron rod through the head of railroad foreman Phineas Gage; his survival and recovery influenced 19th-century discussion of psychology and neuroscience.
- 1919 – The Boston police strike ended after four days of rule by the state militia, the deaths of nine people, and accusations that striking officers were "agents of Lenin".
- 2005 – A software bug caused a simulated pandemic in the online video game World of Warcraft, serving as a model for epidemiologists to understand how human interaction influences disease outbreaks.