Classical mythology is the collective myths and religious structures of the Hellenic and post-Hellenic era. This encompasses the entirety of Greek mythology and covers the transition to Roman mythology as well. Classic mythology as a formal academic discipline is the study of the Greek and Roman gods along with the stories and folktales of heroes performing legendary feats. The stories begin with the creation myth of the Titans, who were the progenitors of the gods and goddesses in Greek polytheism. Generally, the myths and narratives that comprise classical mythology deal with supernatural explanations for natural occurrences.
The Homeric epic poems are two of the most important texts in classical mythology. The Iliad and the Odyssey deal with the Trojan war and its aftermath, intermingling the stories of soldiers and heroes with the gods and goddesses who influenced it. The Iliad details the events of the war in which Achilles, who has been offered a choice between a long, fruitful, and anonymous life and the chance for eternal glory through death in battle, chooses the latter. The Odyssey describes the homeward journey of Odysseus after the Trojan war ends. Many mythic elements are incorporated into the poem, including witchcraft, giants, angry deities, and a journey to the underworld.
Many of the myths in ancient Greek culture use the gods and goddesses to explain the source of objects, events, or processes in the natural world. For example, the myth of Persephone and Demeter explains the annual cycle of the seasons, particularly the origin of winter. Hades, lord of the underworld, kidnaps Persephone for his bride. Demeter, goddess of fertility and agriculture, is angry and stops the crops from growing. A compromise is reached in which Persephone spends the time between fall and spring in the underworld, resulting in the infertile months of winter.
As the Greek empire gave way to the Roman empire, the Romans appropriated many of the Greek folktales and myths, turning them into a distinctly Roman classical mythology. Virgil's Aeneid is similar to Homer's epic poems in plot and structure, except that the hero, Aeneas, fights for the Trojans, not the Achaeans. The hero's journey involves establishing a new home in Italy that would blossom into the Roman Empire. Many of the gods and goddesses of the Roman pantheon were borrowed from earlier Greek counterparts. For example Mercury was based on Hermes, Venus on Aphrodite, and Mars on Ares.