Greek and Roman gods: equivalents and where they differ

The short answer

The table below pairs fourteen Greek gods with their standard Roman counterparts. Apollo is the one god in it who carries the same name on both sides, and Dionysus is matched with Liber, a Roman god often treated as interchangeable with Bacchus and Dionysus.

Several Roman gods had their own temples, festivals and functions, and the sources read for this page record where they differ from the Greek god they are paired with. Mars was more widely honored than Ares, Neptune began as a god of fresh water, and Diana had an independent origin in Italy.

How the matching was done

Ancient writers matched foreign gods to their own as a habit. The Greek version is called interpretatio graeca. Herodotus used it to equate Egyptian gods with Greek ones, for example Amon with Zeus. The Roman version, interpretatio romana, takes its name from Tacitus, who used the phrase in the Germania.

For Greek and Roman gods, the earliest ceremony in the sources read for this page is a lectisternium held at Rome in 399 BC, a ritual in which couches were set out for the gods. Three couches were prepared for three pairs of gods: Apollo and Latona, Hercules and Diana, Mercury and Neptune. Livy 5.13 is the cited source, and he describes the ceremony as happening for the first time. A later one in 217 BC honored six pairs of gods corresponding to the twelve Olympians, with the Roman names Jupiter, Juno, Neptune, Minerva, Mars, Venus, Apollo, Diana, Vulcan, Vesta, Mercury and Ceres.

Wikipedia reports both ceremonies. Its entry for 217 BC cites a 1911 encyclopedia, not an ancient writer, and neither Livy nor any other ancient text was opened directly for this page.

The pair table

Each row gives the Greek god, the Roman counterpart, a strength mark and the main difference recorded in the sources. The marks are explained at the end of the article.

Where the Roman god differs from the Greek one

Jupiter, Juno and Minerva

Britannica calls Jupiter the chief ancient Roman and Italian god, a sky god who oversaw oaths, treaties and leagues. It describes him as etymologically identical with Zeus, from a root, diu, that means bright. The great temple on the Capitol was dedicated to Jupiter Optimus Maximus, with Juno and Minerva associated with him, and its dedication festival fell on 13 September. Britannica notes that placing three deities in one temple was foreign to early Roman religion but occurs in Greece and Etruria, which suggests a Greco-Etruscan origin.

Juno covered every aspect of the life of women, most of all married life. As Juno Lucina she was the goddess of childbirth, with a temple on the Esquiline from the 4th century BC. As Juno Moneta, the Warner, she had a temple on the Arx from 344 BC. The Roman mint was housed there, and Britannica says the words mint and money derive from her name.

Minerva's origin is less settled. Britannica says some scholars believe her cult was that of Athena, introduced to Rome from Etruria. She was a goddess of handicrafts, the professions, the arts and, later, war. By Pompey's time she had been identified with Athena Nike, the bestower of victory.

Mars and Ares

Britannica says Ares was never very popular in Greece and his worship was not widespread. It describes him as the unpleasant side of war, the brutal violence and killing. Mars held a larger place in Rome. His spring and autumn festivals marked the start and end of both the agricultural and the military seasons. The Salii priests danced for him in March, and the Arval Brothers invoked him to keep enemies away from crops and herds.

Under Augustus he became Mars Ultor, the emperor's personal guardian, and by about AD 250 he was the most prominent of the military gods worshiped by the legions. In one myth Mars fathered Romulus and Remus with Rhea Silvia, a Vestal Virgin. Britannica adds that in literature and art Mars is hardly distinguished from Ares.

Neptune and Poseidon

Britannica states that Neptune was originally the god of fresh water. His festival, the Neptunalia, was held on 23 July, in midsummer when water was scarcest, and the page suggests its purpose was probably to appease the freshwater deity. By 399 BCE he was identified with Poseidon, which made him a sea god. Britannica says he took on the Greek god's identity, and in art he appears with Poseidon's trident and dolphin.

Vesta and Hestia

Britannica says Vesta was identified with Hestia. Both are hearth goddesses, and the Roman side adds an organized state cult. Vesta was honored in every household alongside the Penates and Lares. In the Forum a perpetual public fire burned in her circular temple, attended by the Vestal Virgins. The fire was put out and relit each year on 1 March, and an extinction at any other time was a portent of disaster for Rome. The Vestalia ran from 7 to 15 June, and its days were considered unlucky.

Diana and Artemis

Wikipedia gives Diana an independent origin in Italy and says her role in the underworld appears to pre-date strong Greek influence. Her main sanctuary was a woodland grove overlooking Lake Nemi, where worship is attested from at least the 6th century BCE and the Nemoralia was held each August. She absorbed much of Artemis's mythology early in Roman history, and by the 3rd century CE she had been almost fully combined with Artemis. The entry notes that the dual role of civilization and wilderness first applied to the Greek goddess.

Venus and Aphrodite

Wikipedia calls Venus perhaps the most original creation of the Roman pantheon and says she seems to have had no origin myth until her association with Aphrodite. Her oldest festival was probably the Vinalia Rustica, tied to her earliest known form, Venus Obsequens. Q. Fabius Gurges vowed the first known temple to Venus Obsequens during a battle against the Samnites, and it was dedicated in 295 BC near the Aventine Hill. Venus Genetrix, Venus the Mother, was regarded as the ancestress of the Julian family, and Julius Caesar dedicated her temple in 46 BC. In Virgil's account Venus is the mother and protector of Aeneas.

Mercury and Hermes

Britannica describes Mercury as the god of shopkeepers and merchants, travelers and transporters of goods, with thieves and tricksters among his domains. It says he is commonly identified with Hermes, the fleet-footed messenger of the gods. Tradition holds that his temple on the Aventine Hill was dedicated in 495 BCE, and the Mercuralia on 15 May marks that day and honored Mercury and Maia.

Ceres and Demeter

Ceres was the goddess of the growth of food plants, sometimes worshiped alone and sometimes with the earth goddess Tellus. Her temple on the Aventine Hill was built in 493 BC and became a center of plebeian religious and political activity. A fire destroyed it in 31 BC and Augustus restored it. Britannica says that at an early date her cult was overlaid by that of Demeter, who was widely worshiped in Sicily and Magna Graecia, and that the three chief festivals of Ceres followed Greek lines.

Vulcan and Hephaestus

Wikipedia says the Romans identified Vulcan with the Greek smith-god Hephaestus. Vulcan was the god of fire, which covers volcanic fire, desert fire, metalworking and the forge, and his festival, the Vulcanalia, was celebrated on 23 August each year.

Liber, Bacchus and Dionysus

Wikipedia says Liber was closely, often interchangeably, identified with Bacchus, Dionysus and their mythology, though not entirely absorbed by them. It notes that Cicero could insist on the non-identity of Liber and Dionysus. The public Liberalia was held in Rome on 17 March. The Senate's decree of 186 BC, the Senatus consultum de Bacchanalibus, did not ban the Bacchanalia outright. It placed them under official regulation with severe penalties, limited each cult meeting to five initiates and required a praetor's consent. Some 6,000 people are thought to have been executed.

Pluto, Dis Pater and Hades

Wikipedia says Dis Pater, usually taken to mean Rich Father, is perhaps a direct translation of Plouton. Hades was the god's earlier name, which later became the name of the underworld itself, and the page says Pluto and Hades differ in character but are not distinct figures. In the mid-1st century BC Cicero wrote that the earth in all its power and plenty is sacred to Father Dis, and he linked the name to Dives, the wealthy one. The entry also notes that Ennius treated Pluto as a Greek god to be explained through Dis Pater and Orcus.

Apollo

Apollo is the one god in the table whose name did not change. Wikipedia says his worship was imported to Rome in the 5th century BC. The first temple, dated to 431 BC, was dedicated to Apollo Medicus, the doctor, after a plague in 433 BC. Augustus dedicated the temple of Apollo Palatinus on the Palatine Hill in 28 BC, and the Wikipedia article on interpretatio graeca says Augustus made Apollo a patron deity.

What the strength marks mean

Attested means a source read for this page names an ancient writer, a dated act or a dated temple connected with the pairing. For Poseidon and Neptune that is the identification by 399 BCE that Britannica reports. For Hades and Pluto it is Cicero in the mid-1st century BC, and for Dionysus and Liber it is Cicero's insistence that the two were different. Apollo is marked Attested because the temple dates are recorded.

Scholarly means the sources state or assume the pairing, as Britannica does for Mars and Ares and Wikipedia does for Vulcan and Hephaestus, without naming an ancient writer who made the match. No pair in this table falls under Popular claim. The ancient texts, Livy and Cicero included, were read only through these reference pages, so a row marked Attested rests on what the reference page reports about them.