The Aquilii family, some of whose members were among the conspirators and who were the owners of Vindicius, demanded that he be surrendered to them. Valerius refused, and instead freed Vindicius and made him a Roman citizen, thus setting a precedent for other freed slaves to become citizens.
The conspiracy having failed, the Tarquins tried to return by force, and allied themselves with the Etruscan towns of Veii and Tarquinii, their ancestral town, to attack Rome. Valerius and Brutus led out the Roman troops into battle. Both sides lost many men - Brutus was among the slain - but during the night a mysterious voice was heard coming from a nearby wood, saying that the Etruscans had lost one more man than the Romans, and the Romans had therefore won.
Valerius returned to Rome to celebrate his triumph and hold Brutus' funeral. Valerius did not immediately hold elections for a consul to succeed Brutus and was building a magnificent new house for himself. Rumours spread that he wanted to make himself king. When he heard of the rumours, Valerius demolished the house, and stayed with friends until he had had a more modest house built. He also started the custom of the consuls lowering the fasces (the rods carried by their attendants) when they came into assemblies as a sign that they derived their power from the people.
Before holding elections for a colleague to be elected, Valerius enacted some important legislation: the right of appeal to the people from magistrates' judgements; capital punishment for assuming a magistracy not granted by the people; the abolition of taxes on citizens; a fine for disobeying the consuls; loss of civil rights for plotting the return of the monarchy; and death without trial for plotting to make oneself king. He also instituted the public treasury in the temple of Saturn and the election of quaestors to administer it. Because these measures were considered to be in the interests of the common people rather than the patricians, Valerius was granted the new name of Publicola (sometimes spelt Poplicola), meaning People-Minder. The elections for a consul to replace Brutus then went ahead and Spurius Lucretius was elected. However, he died a few days later and another election had to be held. Marcus Horatius was then elected for the remainder of the year.
Publicola was elected consul for the next year (508) with Titus Lucretius. The Tarquins had enlisted on their side Lars Porsena, the king of Clusium. He proceeded to besiege Rome. (508-7). Publicola was elected consul for the third time (507). Lars Porsena was won over by the bravery of Gaius Mucius, who was caught in an attempt to assassinate him, and lifted the siege. Publicola offered to submit Rome's dispute with the Tarquins to Lars Porsena's arbitration, confident that the Tarquins would refuse to do likewise.
