in Roman religion, brother and sister, respectively, originally fire deities of the early Roman settlement on the Palatine Hill, where “Cacus' stairs” were later situated. The Roman poet Virgil (Aeneid, Book VIII) described Cacus as the son of the flame god Vulcan and as a monstrous fire-breathing brigand who terrorized the countryside. He stole some of the giant Geryon's cattle from the hero Hercules (Heracles) and hid them in his lair on the Aventine Hill; but a lowing cow betrayed Cacus, and Hercules, bursting in, killed him. There are various versions of this story, which is traditionally connected with the establishment of Hercules' oldest Roman place of worship, the Ara Maxima, in the Forum Boarium (Cattle Market), whose name is believed to commemorate these events.