509 BCE
The Temple of Jupiter Optimus Maximus on Rome's Capitoline Hill is dedicated on the ides of September. The Roman monarchy is overthrown, and the Republican period begins (traditional date). Forces of Veii and Tarquinii, led by the deposed king Lucius Tarquinius Superbus, are defeated in the Battle of Silva Arsia by the Roman army. Consul Publius Valerius Publicola celebrates the first republican triumph on March 1.
Geopolitics & Diplomacy
Conflict & Security
- Forces of Veii and Tarquinii, led by the deposed king Lucius Tarquinius Superbus, are defeated in the Battle of Silva Arsia by the Roman army. Consul Publius Valerius Publicola celebrates the first republican triumph on March 1.source
Religion & Belief
- September 13—The Temple of Jupiter Optimus Maximus on Rome's Capitoline Hill is dedicated on the ides of September.source
Crime & Justice
- The Tarquinian conspiracy is formed yet discovered, and the conspirators are executed.source
Deaths
- Lucius Junius Brutus, Roman consul and founder of the Roman Republic (traditional date)source
- Aruns, son of the last Roman king Lucius Tarquinius Superbussource
- Spurius Lucretius Tricipitinus, Roman consul suffectussource
- Titus Junius Brutus and Tiberius Junius Brutus, brothers (and sons of the consul Lucius Junius Brutus) together with their two uncles the Vitellii and three brothers Aquillii, all executed following the discovery of the Tarquinian conspiracysource