Greek and Roman gods: the names compared

The ancient Greeks believed in many gods. The most important gods lived on Mount Olympus, the highest mountain in Greece, so they are called the Olympian gods. The Greeks thought that the gods looked like people, but they were much stronger and they never died.

The king of the gods was Zeus, the god of the sky and of thunder. The poet Hesiod tells his story in a long poem, the Theogony, «the birth of the gods». After a great war against the Titans, the other gods asked Zeus to be their king, and Zeus shared out the honours among them (Theogony 881–885). Each god looked after something different. Hera was the queen of the gods, Poseidon ruled the sea, Athena was the goddess of wisdom, and Hermes carried the messages of the gods. The Greek word for a god is θεός, and Greeks still use the same word today.

The Romans lived in Italy. They had their own old gods, with Latin names. Jupiter was their god of the sky, and Juno was his wife. The Romans met the Greeks through trade and through the Greek cities of southern Italy. They heard Greek stories and saw Greek statues. Little by little, they decided that their gods were the same as the Greek ones. So Jupiter was matched with Zeus, Juno with Hera, and Mercury with Hermes.

Some names are even related. The name Jupiter comes from an old form, Jovis-pater, «father Jovis». Dictionaries of Latin link Jovis to the Greek name Ζεύς and to a very old word meaning «to shine», like the bright sky. One Greek god, Apollo, did not need a new name at all. In the 5th century BC, during a terrible illness, the Romans promised Apollo a temple and asked him to protect the people's health. They kept his Greek name (Livy 4.25 and 4.29).

In 217 BC, Rome was in great danger, in a war against Hannibal. The Romans held a feast for twelve gods, placed in pairs on six couches: Jupiter with Juno, Neptune with Minerva, Mars with Venus, Apollo with Diana, Vulcan with Vesta, and Mercury with Ceres (Livy 22.10). Here are the same twelve gods, Greek name first and Roman name second:

• Zeus (Ζεύς) – Jupiter, king of the gods
• Hera (Ἥρα) – Juno, queen of the gods
• Poseidon (Ποσειδῶν) – Neptune, god of the sea
• Athena (Ἀθηνᾶ) – Minerva, goddess of wisdom
• Ares (Ἄρης) – Mars, god of war
• Aphrodite (Ἀφροδίτη) – Venus, goddess of love and beauty
• Apollo (Ἀπόλλων) – Apollo, god of music and light
• Artemis (Ἄρτεμις) – Diana, goddess of hunting
• Hephaestus (Ἥφαιστος) – Vulcan, god of fire and metalwork
• Hestia (Ἑστία) – Vesta, goddess of the home fire
• Hermes (Ἑρμῆς) – Mercury, messenger of the gods
• Demeter (Δημήτηρ) – Ceres, goddess of grain and harvest

The matching is not perfect. Each Roman god also kept old Roman customs and stories of its own.

Look at the night sky. Some bright «stars» move slowly from night to night. The Greeks called them πλανῆται, «wanderers», and that is where the word planet comes from. In ancient Greek, a planet was named after a god: «the star of Zeus», «the star of Hermes», «the star of Aphrodite». The Romans gave the planets the names of their own gods, and English and many other languages took the Roman names: Mercury, Venus, Mars, Jupiter and Saturn.

Modern Greek kept the Greek names. A Greek pupil learns that the planets are Ερμής (Mercury), Αφροδίτη (Venus), Γη (Earth), Άρης (Mars), Δίας (Jupiter), Κρόνος (Saturn), Ουρανός (Uranus) and Ποσειδώνας (Neptune). Neptune was discovered only in 1846 and got the Latin name of the sea god, so Greek simply translated it as Ποσειδώνας. And the modern name Δίας comes from Δία, another ancient form of the name Zeus.