Tiberius and his elder brother Titus Junius Brutus were monarchists and rebelled against the new republic together with Lucius Tarquinius Superbus. According to Livy, the cause was betrayed to the consul by Vindex, a slave of Tiberius jealous for being replaced by another lover, Aemus Aemilius Mamercus, who was to become the ancestor of the Aemilii. The conspirators were put to death by Lucius Junius Brutus, the consul and father of Tiberius Junius Brutus.
Tiberius and Titus were captured and brought before the embryonic Senate of Rome who, according to historian Lavilius, consisted of many ancestors of later Roman notables, e.g., Numerius Iulius Iullus (ancestor of Julius Caesar ), Quintus Cassius Vercellinus (ancestor of Cassius Longinus ) and Sergastus Sergius Sorgo (ancestor of Lucius Sergius Catilina). Livy tells that the jurors pleaded for them to be pardoned, but Lucius Brutus called for their execution, and they were beheaded, thus ending the patrician clan of the Junii.
Tiberius was married to the granddaughter of Numa Pompilius, Pompilia, and had a daughter, Junia. Her son, Gaius Larcius , a patrician, was adopted by the plebeian cousin of Tiberius, Gnaeus Junius Brutus, and took the name Gnaeus Junius Brutus. From this family the Junii continued, the two sons of Gnaeus being Decimus Junius Silanus and Quintus Junius Brutus, the ancestor of Marcus Junius Brutus, one of the assassins of Caesar.