Head of the Roman state cult; senior member of the Capitoline triad (with Iuno and Minerva). Distinct from Greek Zeus despite cognate Indo-European origin — Roman Iuppiter's cult is institutionally embedded in the Roman state in ways Zeus's never was: the consul's oath of office, the triumph terminus, the spolia opima at Feretrius, the flamen Dialis taboo system, the Capitoline triad temple sharing. The triumphator literally enacted Iuppiter on the triumph route — quadriga, vermilion face, laurel crown — climaxing at the Capitoline temple where the laurel branch went into the god's lap. Per Beard/North/Price, Religions of Rome (1998); Wissowa, Religion und Kultus der Römer (1912); Dumézil, Archaic Roman Religion (1970); Coarelli, Il Foro Romano (1983-85).