However, in some sources they are described as grandsons; their father may have been a certain Gnaeus Tarquinius, who according to an Etruscan tradition was defeated and killed by the heroes Aulus and Caelius Vibenna, together with a certain Macstarna.
Apparently the Etruscan equivalent of the Latin word magister, Macstarna has been identified with Servius Tullius, the sixth King of Rome.
Arruns' wife, known to history as Tullia Minor, as she was the younger daughter, was similarly ambitious, while her elder sister was not.
But as Arruns lacked the ambition to overthrow his father-in-law, Tullia contrived his murder, and that of her own sister, that she might marry Lucius.
With a sudden and bloody palace coup, the pair deposed and murdered the king, and Lucius seized the throne.