Two names, one god
If you only need a one-line answer, Pluto is Hades. Both names belong to the son of Cronus and Rhea who rules the dead with Persephone at his side, and later Roman writers used them interchangeably. The difference is in where each name came from, what it meant, and which side of the god it stressed.
| Hades | Pluto (Plouton) | |
|---|---|---|
| Language of origin | Greek (Haides) | Greek title (Ploutōn), later Latinized as Pluto |
| Usual meaning given | "The unseen one" | "The rich one" |
| When it is attested | Homer and Hesiod onward | Common from around the 5th century BC |
| Tone in myth | Dark, feared; the violent abductor of Persephone | Stern but benevolent; Persephone's husband in the Eleusinian Mysteries |
| Typical attribute in art | Sometimes an empty drinking horn | Sceptre and an overflowing cornucopia |
| Roman counterparts | Dis Pater and Orcus, both merged into the Roman Pluto | |
What each name means
The origin of the name Hades is uncertain. Since antiquity it has usually been explained as "the unseen one," and modern linguists have proposed a Proto-Greek form *Awides with that meaning. Plato's Cratylus, which spends a long passage on the god's name, has Socrates argue for a different folk etymology linking it to his knowledge of all noble things, a reminder that even the Greeks were unsure.
Plouton is clearer. Its root means "wealthy," from the idea that riches come up from below: crops grow out of the soil, and metals are dug from under it. Around the 5th century BC, the Greeks began calling the god Plouton instead of Hades. One common explanation is that people were reluctant to say the real name of the lord of the dead, and that a flattering title was safer.
The Greek split: a feared god and a generous one
In Greek religion the two names were not interchangeable, and each stressed a different side of the god. Under the name Hades he had few temples and religious practices associated with him, and myth portrays him as the dark and violent abductor of Persephone. Art shows the same fear of him: he was depicted relatively rarely, because the Greeks were so afraid of him.
Plouton was a different face of the same power. The name spread through the Eleusinian Mysteries, which honored Pluto and Persephone as a divine couple who received initiates after death. In that setting he is a stern ruler and a husband, not a kidnapper. Vase painters marked the difference with props. Plouton's most common attribute is a sceptre, and he often holds a full or overflowing horn of plenty. When Hades holds a horn, it is empty and should be read as a drinking horn.
The wealth theme also brought in a near-namesake. Hesiod's Theogony makes Ploutos, "Wealth," a son of Demeter and Iasion, and in later tradition this Plutus blended into the figure of Pluto, Demeter's son-in-law.
How Rome turned Plouton into Pluto
Rome already had its own underworld powers. Dis Pater was a Roman god first tied to fertile farmland and mineral wealth. His name is a contraction of the Latin dives, "rich," so it covers the same ground as Plouton, and Cicero in De Natura Deorum gave a similar "father of riches" etymology and compared it with the Greek name. Orcus was an older, obscurer Roman figure whose name, like Hades, meant both a god of the dead and the place of the dead.
Roman-era mythographers equated Dis Pater and Orcus with Hades and folded them both into Pluto. The poet Ennius, around the late 3rd and early 2nd centuries BC, already treated Pluto as a Greek god to be explained through the Roman Dis Pater and Orcus. Some scholars think Pluto's rites entered Roman religion with the Saecular Games in 249 BC, and that Dis Pater began as a translation of Plouton. The Roman Senate ordered festivals to appease Dis Pater and Proserpina in 249 and 207 BC, and offerings during the games were made at an underground altar in the Tarentum, at the edge of the Campus Martius. That altar was rediscovered in 1886 and 1887 beneath Corso Vittorio Emanuele in Rome.
By the Middle Ages and Renaissance, and certainly by Natale Conti's Mythologiae of 1567, the stories had merged into a single mythology that drew few if any distinctions among Hades, Pluto, Dis and Orcus. That is the version most readers inherit today.
Same family, same realm
The family tree does not change with the name. In the Greek telling, Hades is the eldest son of Cronus and Rhea, which also made him the last of the sons his father had swallowed to be brought back up. In the Roman version, Dis Pater as Pluto is one of the three sons of Saturn and Ops, alongside Jupiter and Neptune, and rules the dead with Proserpina.
How the brothers divided the world also has more than one version. In the Iliad, Poseidon says, in Richmond Lattimore's translation, that the three of them drew lots: he drew "the grey sea," Hades "the mists and the darkness," and Zeus "the wide sky." Earth and Olympus stayed common to all three. Hesiod's Theogony gives a different account, in which Zeus overthrows his father and is acclaimed king by the other gods. The Homeric Hymn to Demeter calls him Aidoneus, "Ruler of Many," who holds "that third share which he received when division was made at the first."
For the brothers he drew against, see our Zeus and Poseidon profiles, and for his marriage, Persephone and Hades.
Where the Roman names turn up later
The Roman names kept living after the cults ended. Dis Pater's name was commonly shortened to Dis, and Dis became another word for the underworld or part of it. The best-known example is the City of Dis in Dante's Divine Comedy, which takes in the whole of Lower Hell. In Latin literature, Dis was also used as a poetic stand-in for death itself.
Julius Caesar, in his Commentaries on the Gallic War (VI.18), says that the Gauls all claimed descent from Dis Pater. That is a Roman habit called interpretatio romana: Caesar was matching an unnamed Gaulish god to the nearest Roman one, and scholars still disagree about which Gaulish deity he meant. So when you read "Pluto," "Dis" or "Orcus" in a Roman text, the writer usually means the same lord of the dead the Greeks called Hades, seen through Roman eyes.
And the dwarf planet?
The ninth-planet-turned-dwarf-planet takes its name from the Roman god, not from the Greek name. NASA records that in 1930 Venetia Burney, an 11-year-old in Oxford, England, suggested to her grandfather that the newly found world be named after the Roman god of the underworld. Her grandfather, Falconer Madan, passed the idea along, and the name stuck. The name then passed to chemistry. Los Alamos National Laboratory records that plutonium was first made in December 1940 at the University of California, Berkeley, and that, because element 93 had just been named neptunium after Neptune, the new element 94 was named for the next planet out, Pluto.