Tarquinius, name of an illustrious Roman family of Etruscan origin, two of whose members, according to legend, reigned as king in Rome: Lucius Tarquinius Superbus, fifth king of Rome; the friend and successor of Ancus Martius; said to have reigned from 616 to 578 B.C., and to have greatly extended the power and fame of Rome; was murdered by the sons of Ancus Martius. Lucius Tarquinius Superbus, seventh and last king of Rome (534-510), usurped the throne after murdering his father-in-law, King Servius Tullius; ruled as a despot, extended the power of Rome abroad, but was finally driven out by a people goaded to rebellion by his tyranny and infuriated by the infamous conduct of his son Sextus (the violator of Lucretia); made several unsuccessful attempts to regain the royal power, failing in which he retired to Cumæ, where he died.