According to Livy and Plutarch, the Valerii were of Sabine origin, but settled in Rome during the reign of Titus Tatius, a contemporary of Romulus, and worked for the peaceful unification of both peoples.

[3] From exile, the Tarquins plotted the assassination of the consuls, together with some disaffected members of the Aquillii and Vitellii, who had benefited from the deposed regime.

He personally investigated the conspiracy, sneaking into the Aquillius estate and finding incriminating evidence, based on which the consuls held a public trial.

[1] After the trial, Brutus demanded that his colleague, Collatinus, resign the consulship and go into exile, as a member of the hated royal family, whom the people could not trust.

Collatinus was stunned by this betrayal, as he had been one of the leaders of the rebellion following his wife Lucretia's suicide because of her being raped by the king's son, Sextus Tarquinius.

Arruns Tarquinius, the king's son, died in combat with Brutus, who was also mortally wounded, but the Romans were ultimately victorious.

[3] Addressing an assembly of the people, he caused his lictors to lower their fasces as a mark of humility, and to remove the axes from them within the city.

Although diplomatic negotiations were halted, Poplicola meddled with the politics of the Sabines, assisting Attius Clausus, who moved to Rome with five hundred followers.

When the Sabines attempted to besiege Rome, Poplicola successfully commanded the army, anticipating their movements and thwarting their plans.

Livy records that at the time of his death, he was considered "by universal consent to be the ablest man in Rome, in the arts both of peace and war".

The Lapis Satricanus dates from the late 6th to early 5th centuries BC[14] and bears the name Poplios Valesios, which would be rendered in Classical Latin as Publius Valerius.

This does not prove the historicity of the narrative given by later Roman historians, but it does demonstrate that at least one prominent individual did indeed bear the name at the close of the 6th century.

In The Federalist Papers, a collection of 85 essays promoting the adoption of the United States Constitution, written by Alexander Hamilton, James Madison, and John Jay in 1787–1788, the three statesmen used the allonym "Publius" in honor of Poplicola's role in establishing the Roman Republic.