Greek mythology is known today primarily from Greek literature and representations on visual media dating from the Geometric period from c. 900 BC to c. 800 BC onward. In fact, literary and archaeological sources integrate, sometimes mutually supportive and sometimes in conflict; however, in many cases, the existence of this corpus of data is a strong indication that many elements of Greek mythology have strong factual and historical roots.
Mythical narration plays an important role in nearly every genre of Greek literature. Nevertheless, the only general mythographical handbook to survive from Greek antiquity was the Library of Pseudo-Apollodorus. This work attempts to reconcile the contradictory tales of the poets and provides a grand summary of traditional Greek mythology and heroic legends. Apollodorus of Athens lived from c. 180 BC to c. 125 BC and wrote on many of these topics. His writings may have formed the basis for the collection; however the "Library" discusses events that occurred long after his death, hence the name Pseudo-Apollodorus.
Among the earliest literary sources are Homer's two epic poems, the Iliad and the Odyssey. Other poets completed the "epic cycle", but these later and lesser poems now are lost almost entirely. Despite their traditional name, the "Homeric Hymns" have no direct connection with Homer. They are choral hymns from the earlier part of the so-called Lyric age. Hesiod, a possible contemporary with Homer, offers in his Theogony (Origin of the Gods) the fullest account of the earliest Greek myths, dealing with the creation of the world; the origin of the gods, Titans, and Giants; as well as elaborate genealogies, folktales, and etiological myths. Hesiod's Works and Days, a didactic poem about farming life, also includes the myths of Prometheus, Pandora, and the Five Ages. The poet gives advice on the best way to succeed in a dangerous world, rendered yet more dangerous by its gods.
Lyrical poets often took their subjects from myth, but their treatment became gradually less narrative and more allusive. Greek lyric poets, including Pindar, Bacchylides and Simonides, and bucolic poets such as Theocritus and Bion, relate individual mythological incidents. Additionally, myth was central to classical Athenian drama. The tragic playwrights Aeschylus, Sophocles, and Euripides took most of their plots from myths of the age of heroes and the Trojan War. Many of the great tragic stories (e.g. Agamemnon and his children, Oedipus, Jason, Medea, etc.) took on their classic form in these tragedies. The comic playwright Aristophanes also used myths, in The Birds and The Frogs.
Historians Herodotus and Diodorus Siculus, and geographers Pausanias and Strabo, who traveled throughout the Greek world and noted the stories they heard, supplied numerous local myths and legends, often giving little-known alternative versions. Herodotus in particular, searched the various traditions presented him and found the historical or mythological roots in the confrontation between Greece and the East. Herodotus attempted to reconcile origins and the blending of differing cultural concepts.
The poetry of the Hellenistic and Roman ages was primarily composed as a literary rather than cultic exercise. Nevertheless, it contains many important details that would otherwise be lost. This category includes the works of:
- The Roman poets Ovid, Statius, Valerius Flaccus, Seneca and Virgil with Servius's commentary.
- The Greek poets of the Late Antique period: Nonnus, Antoninus Liberalis, and Quintus Smyrnaeus.
- The Greek poets of the Hellenistic period: Apollonius of Rhodes, Callimachus, Pseudo-Eratosthenes, and Parthenius.
Prose writers from the same periods who make reference to myths include Apuleius, Petronius, Lollianus, and Heliodorus. Two other important non-poetical sources are the Fabulae and Astronomica of the Roman writer styled as Pseudo-Hyginus, the Imagines of Philostratus the Elder and Philostratus the Younger, and the Descriptions of Callistratus.
Finally, a number of Byzantine Greek writers provide important details of myth, much derived from earlier now lost Greek works. These preservers of myth include Arnobius, Hesychius, the author of the Suda, John Tzetzes, and Eustathius. They often treat mythology from a Christian moralizing perspective.
The Roman poet Virgil
, here depicted in the fifth-century manuscript, the Vergilius Romanus
, preserved details of Greek mythology in many of his writings.
The discovery of the Mycenaean civilization by the German amateur archaeologist Heinrich Schliemann in the nineteenth century, and the discovery of the Minoan civilization in Crete by the British archaeologist Sir Arthur Evans in the twentieth century, helped to explain many existing questions about Homer's epics and provided archaeological evidence for many of the mythological details about gods and heroes. Unfortunately, the evidence about myths and rituals at Mycenaean and Minoan sites is entirely monumental, as the Linear B script (an ancient form of Greek found in both Crete and mainland Greece) was used mainly to record inventories, although certain names of gods and heroes have been tentatively identified.
Geometric designs on pottery of the eighth century BC depict scenes from the Trojan cycle, as well as the adventures of Heracles. These visual representations of myths are important for two reasons. Firstly, many Greek myths are attested on vases earlier than in literary sources: of the twelve labors of Heracles, for example, only the Cerberus adventure occurs in a contemporary literary text. Secondly, visual sources sometimes represent myths or mythical scenes that are not attested in any extant literary source. In some cases, the first known representation of a myth in geometric art predates its first known representation in late archaic poetry, by several centuries. In the Archaic (c. 750 – c. 500 BC), Classical (c. 480–323 BC), and Hellenistic (323–146 BC) periods, Homeric and various other mythological scenes appear, supplementing the existing literary evidence.