Rome had three gods of the dead and never reduced them to one. Dis Pater, whose name is a Latin translation — dis from dives, rich — of the Greek euphemism Plouton, "the wealthy one", the god who owns what is buried. Orcus, an older and grimmer figure with an Etruscan look to him, the personification of death itself and of the punishment beyond it. And Pluto, the Greek name arriving with the literature. Latin authors use all three, sometimes in the same work, sometimes as synonyms and sometimes not.
That untidiness is characteristic. Roman religion accumulated rather than harmonised, and only a modern handbook feels obliged to make one entry out of three.
The altar that was kept buried
The one securely Roman cult of Dis Pater sat in a spot on the Campus Martius called the Tarentum, where an altar to him and to Proserpina stood under about twenty feet of earth. It was dug out only for the Ludi Saeculares, the Secular Games, held to mark the end of a saeculum — the longest span a human life could cover — and then covered over again.
The foundation legend attaches it to a Sabine named Valesius whose children fell ill and who was told to take them to Tarentum and give them water heated on the altar of Dis and Proserpina; digging on the Campus Martius he found the altar already there, and the children recovered.
What makes this cult unusually recoverable is that the proceedings were inscribed. A large marble record of Augustus's games of 17 BCE survives, listing the sacrifices, the nights of ritual, and the performance by twenty-seven boys and twenty-seven girls of a hymn commissioned from Horace — the Carmen Saeculare, which we therefore possess both as a poem and as an item on a religious invoice. It is one of the few points in ancient religion where the liturgy, the score and the receipt all survive.
Black victims and averted faces
Roman practice towards the gods below inverted the ordinary rules. Sacrifices to them used black animals, took place at night or at dusk, were made in a pit or on a low altar rather than a raised one, and the offering was burned entire rather than shared in a meal — because there is no dining with the dead. The officiant turned his face away. Where a prayer to Jupiter was made with the hand raised palm-up, the chthonic gesture was to point the palm down and strike the ground.
None of that requires a myth to explain it, and Rome had barely any myth here of its own. The abduction of Proserpina, her mother Ceres's search and the pomegranate seeds all arrive from Greece; the Roman contribution is the localisation of the abduction in Sicily and a folk-etymology deriving Proserpina from the verb for a shoot creeping up out of the soil.
Caesar's note on the Gauls
In the Gallic War, Caesar reports that the druids say the Gauls are all descended from Dis Pater, and that this is why they measure time by nights rather than days and count birthdays and the beginnings of months from the preceding night.
Whatever Celtic deity actually stood behind that claim — the identification has been argued over for a century without resolution — the observation about reckoning is independently supported by the Coligny calendar and by the survival of "fortnight" and "sennight" in Germanic languages. It is a good example of a Roman writer preserving a genuine foreign datum inside a misleading Roman label.
Orcus, and a word that went a very long way
Orcus is the darker of the two Latin names, used for the underworld as a place as well as its master, and in later art and folklore he acquires a hammer or mallet — an attribute the Etruscan death-demon Charun also carries, and the painted tomb at Tarquinia known as the Tomb of Orcus takes its modern name from a figure in it.
His name did not die with the religion. Italian orco means an ogre, and French ogre is often derived from the same source, though the etymology is not certain. Old English orcneas, a word in Beowulf for a kind of monstrous creature, may descend from Latin orcus; Tolkien took his orcs from that Old English word, and said so. The chain has several disputed links and a strong probability running through it: the least glamorous of Rome's death-gods is the ancestor of the standard fantasy henchman.
Hades is a different job
Hades in Greece is a god with an unspeakable name, a helmet of invisibility, and virtually no temples — Greeks also avoided him and also used the wealth-euphemism. The overlap is real. What Rome added is the institutional side: the Secular Games as a state instrument for closing an era and starting a new one, and the association of the underworld with wealth as fact rather than metaphor, since Roman mining, treasure and land were all literally under the ground his name claims.
The Roman family tree gives him Saturn and Ops as parents, which is Greek genealogy imported wholesale; no Latin cult evidence makes Dis Pater anyone's son.
The planet, the metal and the dog
Pluto was named in 1930 by an eleven-year-old in Oxford, Venetia Burney, whose suggestion reached Lowell Observatory by telegram and was adopted partly because its first two letters were the initials of Percival Lowell. The element plutonium followed in 1940–41, extending the uranium–neptunium sequence outward one more planet. Disney's dog, introduced in the same period, was named after the newly famous planet rather than the god. And in 2006 the planet's demotion to dwarf planet made a Roman death-god the subject of the most widely followed taxonomic argument in modern astronomy.
The word plutocracy is a near-relation rather than a descendant: it comes from the same Greek ploutos, wealth, that produced the god's by-name, not from the god himself.
Questions about Rome's underworld gods
Did Romans expect judgement after death?
Most of the evidence suggests not, in any systematic way. Ordinary Roman funerary practice concerns itself with correct burial, with the tomb as a place the family visits at the Parentalia, and with the Manes — the collective dead, addressed on gravestones as Dis Manibus, to the divine dead. Elaborate afterlife judgement scenes belong to philosophy, to Greek-derived poetry like the sixth book of the Aeneid, and to the mystery cults, and it is a mistake to read them as standard Roman belief.
Why does he sometimes hold a cornucopia?
Because of the wealth etymology. Both Greek Plouton and Latin Dis are named for riches, and the horn of plenty in the hand of an underworld god is a statement that everything grown comes up from below and everything valuable is mined from there. It also explains the frequent confusion in art between this figure and Plutus, a separate personification of wealth.
Was there a Roman festival of the dead?
Several, and none of them belonged to Pluto. The Parentalia in February honoured family ancestors; the Lemuria in May dealt with restless spirits, with the head of the household spitting black beans over his shoulder at midnight; the Feralia closed the February sequence. Rome's engagement with the dead ran through the household and the tomb rather than through a temple of the underworld's king.
What survives of the Tarentum site?
Little that is visible. Excavations in the Campus Martius in the late nineteenth century recovered the great inscription of the Augustan games and further records of the games held under Septimius Severus in 204 CE, which are now the main evidence for the cult's practice. The altar itself, by the nature of the rite, spent almost all of its existence deliberately buried.