Interpretatio graeca

A Roman fresco from Herculaneum depicting Hercules (from Etruscan Hercle and ultimately Greek Heracles) and Achelous (patron deity of the Achelous River in Greece) from Greco-Roman mythology, 1st century AD

Herodotus was one of the earliest authors to engage in this form of interpretation. In his observations regarding the Egyptians, he establishes Greco-Egyptian equivalents that endured into the Hellenistic era, including Amon/Zeus, Osiris/Dionysus, and Ptah/Hephaestus. In his observations regarding the Scythians, he equates their queen of the gods, Tabiti, to Hestia, Papaios and Api to Zeus and Gaia respectively, and Argimpasa to Aphrodite Urania, whilst also claiming that the Scythians worshipped equivalents to Herakles and Ares, but which he doesn't name.

Some pairs of Greek and Roman gods, such as Zeus and Jupiter, are thought to derive from a common Indo-European archetype (Dyeus as the supreme sky god), and thus exhibit shared functions by nature. Others required more expansive theological and poetic efforts: though both Ares and Mars are war gods, Ares was a relatively minor figure in Greek religious practice and deprecated by the poets, while Mars was a father of the Roman people and a central figure of archaic Roman religion.

Some deities dating to Rome's oldest religious stratum, such as Janus,and Terminus, had no Greek equivalent. Other Greek divine figures, most notably Apollo, were adopted directly into Roman culture, but underwent a distinctly Roman development, as when Augustus made Apollo one of his patron deities. In the early period, Etruscan culture played an intermediary role in transmitting Greek myth and religion to the Romans, as evidenced in the linguistic transformation of Greek Heracles to Etruscan Her[e]cle to Roman Hercules.

The phrase interpretatio romana was first used by the Imperial-era historian Tacitus in the Germania.[4] Tacitus reports that in a sacred grove of the Nahanarvali, "a priest adorned as a woman presides, but they commemorate gods who in Roman terms (interpretatione romana) are Castor and Pollux."[5] Elsewhere,[6] he identifies the principal god of the Germans as Mercury, perhaps referring to Wotan.[7]

Gilt bronze head from the cult statue of Sulis Minerva from the Temple at Bath

Some information about the deities of the ancient Gauls (the continental Celts), who left no written literature other than inscriptions, is preserved by Greco-Roman sources under the names of Greek and Latin equivalents. A large number of Gaulish theonyms or cult titles are preserved, for instance, in association with Mars. As with some Greek and Roman divine counterparts, the perceived similarities between a Gallic and a Roman or Greek deity may reflect a common Indo-European origin.[8] Lugus was identified with Mercury, Nodens with Mars as healer and protector, Sulis with Minerva. In some cases, however, a Gallic deity is given an interpretatio romana by means of more than one god, varying among literary texts or inscriptions. Since the religions of the Greco-Roman world were not dogmatic, and polytheism lent itself to multiplicity, the concept of "deity" was often expansive, permitting multiple and even contradictory functions within a single divinity, and overlapping powers and functions among the diverse figures of each pantheon. These tendencies extended to cross-cultural identifications.[9]

In the Eastern empire, the Anatolian storm god with his double-headed axe became Jupiter Dolichenus, a favorite cult figure among soldiers.

The following is a list of Greek, Roman, Etruscan, Egyptian, Hindu, and Phoenician equivalents, based on usage among the ancients themselves, supported by the analyses of modern scholars. "Equivalent" should not be taken to mean "the same god". For instance, when the myths or even cult practices of a particular Roman deity were influenced by the Greek or Etruscan tradition, the deity may have had an independent origin and a tradition that is culturally distinctive.

Examples of deities depicted in syncretic compositions by means of interpretatio graeca or romana:

• 
  Jupiter Ammon (terracotta of Hellenistic style, 1st century AD)
• 
  Syncretized figure from the Eastern provinces, perhaps a Genius (1st century BC – 1st century AD)
• 
  Isis holding sistrum and oinochoe (Roman marble, reign of Hadrian)
• 
  Isis, Serapis, the child Harpocrates and Dionysos (relief from Roman Africa, late 2nd century AD)
• 
  Worshipper before Zeus–Serapis–Ohrmazd (Bactria, 3rd century AD)

• Aion (deity)
• Mystery religions
• Honji suijaku, in Japan
• Interpretatio Christiana
• Proto-Indo-European religion, a reconstructed religion that relates Greek deities to other Indo-European deities
• Shinbutsu-shūgō, a Japanese amalgamation of Buddhist and Shinto deities
• Syncretism
• Interpretatio germanica

• Assmann, Jan (2008). "Translating Gods: Religion as a Factor of Cultural (Un)Translatability". In de Vries, Hent (ed.). Religion: Beyond a Concept. Fordham University Press. ISBN 9780823227242.
• Kaspers, Wilhelm. "Germanische Götternamen." Zeitschrift Für Deutsches Altertum Und Deutsche Literatur 83, no. 2 (1951): 79-91. www.jstor.org/stable/20654522.
• Pakkanen, Petra (1996). Interpreting Early Hellenistic Religion: A Study Based on the Mystery Cult of Demeter and the Cult of Isis. Foundation of the Finnish Institute at Athens. ISBN 978-951-95295-4-7.