509 BC

Roman Republic

Traditional establishment of the Roman Republic

The first pair of magistrates included a man named Tarquinius. Collatinus had helped expel the royal household, but Romans distrusted his name and pressed him out.

An election, not just an expulsion

The founding is filed here under 510 BCE and customarily dated to 509. Livy places the moment itself in a vote: the centuriate assembly, presided over by the urban prefect Spurius Lucretius, selected Lucius Junius Brutus and Lucius Tarquinius Collatinus as the two new chief magistrates.

The Senate did not simply choose them, as later retellings sometimes have it. Collatinus, Lucretia's husband, was afterwards pressured to resign because he bore the Tarquin name.

Power that expires

The constitutional innovation in the traditional settlement was structural: royal authority was divided between two colleagues rather than held by one man, and their terms ran a single year and then ended. The magistrates were later known as consuls.

Some scholarship holds they may originally have been called praetors, and questions whether the fully developed consulship existed from 509 BCE at all.

What the customary year can carry

The Republic's establishment is customarily dated to 509 BCE rather than to the 510 filed against this entry. Evidence for early republican politics is sparse, late and internally flexible, and the transition may have been a longer institutional process than one revolution and one election.

“Republic” did not mean modern representative democracy either; popular assemblies, aristocratic councils and magistrates shared power in unfamiliar ways, and the mature constitution of the middle and late Republic should not be projected backwards onto it.

The exact list of the first magistrates is a tradition, not a fact confirmed by contemporary records.

Sources

Researched 23 Aug 2026 7 sources 2 audit passes Traditional date

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Traditional date. Conventionally dated here; the research places it at -0509.

What the sources leave uncertain

The Republic’s establishment is customarily dated to 509 BCE, not securely to the listed 510 BCE.
The evidence for early republican politics is sparse, late, and internally flexible. The transition may have been a longer institutional process rather than one revolution and election.
The first magistrates may originally have been called praetors. Some scholarship questions whether the fully developed consulship existed from 509 BCE.