In ancient Roman religion, Ceres (/ˈsɪəriːz/ SEER-eez, Latin: [ˈkɛreːs]) was a goddess of agriculture, grain crops, fertility and motherly relationships. She was originally the central deity in Rome's so-called plebeian or Aventine Triad, then was paired with her daughter Proserpina in what Romans described as "the Greek rites of Ceres". Her seven-day April festival of Cerealia included the popular Ludi Ceriales (Ceres' games). She was also honoured in the May lustratio of the fields at the Ambarvalia festival, at harvest-time, and during Roman marriages and funeral rites.

Ceres is the only one of Rome's many agricultural deities to be listed among the Dii Consentes, Rome's equivalent to the Twelve Olympians of Greek mythology. The Romans saw her as the counterpart of the Greek goddess Demeter, whose mythology was reinterpreted for Ceres in Roman art and literature.

In ancient Greek religion and mythology, Demeter (/dɪˈmiːtər/; Attic: Δημήτηρ Dēmḗtēr [dɛːmɛ́ːtɛːr]; Doric: Δαμάτηρ Dāmā́tēr) is the Olympian goddess of the harvest and agriculture, presiding over grains and the fertility of the earth. She was also called Deo (Δηώ).. Her cult titles include Sito (Σιτώ), "she of the Grain", as the giver of food or grain, and Thesmophoros (θεσμός, thesmos: divine order, unwritten law; φόρος, phoros: bringer, bearer), "giver of customs" and/or "legislator", in association with the secret female-only festival called the Thesmophoria.

Though Demeter is often described simply as the goddess of the harvest, she presided also over the sacred law, and the cycle of life and death. She and her daughter Persephone were the central figures of the Eleusinian Mysteries, a religious tradition that predated the Olympian pantheon, and which may have its roots in the Mycenaean period c. 1400–1200 BC. Demeter was often considered to be the same figure as the Anatolian goddess Cybele, and she was identified with the Roman goddess Ceres.

In Greek mythology, Gaia (/ˈɡeɪə, ˈɡaɪə/;] from Ancient Greek Γαῖα, a poetical form of Γῆ Gē, "land" or "earth"), also spelled Gaea /ˈdʒiːə/, is the personification of the Earth and one of the Greek primordial deities. Gaia is the ancestral mother—sometimes parthenogenic—of all life. She is the mother of Uranus (the sky), from whose sexual union she bore the Titans (themselves parents of many of the Olympian gods), the Cyclopes, and the Giants; as well as of Pontus (the sea), from whose union she bore the primordial sea gods. Her equivalent in the Roman pantheon was Terra.

Hesiod's Theogony tells how, after Chaos, "wide-bosomed" Gaia (Earth) arose to be the everlasting seat of the immortals who possess Olympus above. And after Gaia came "dim Tartarus in the depth of the wide-pathed Earth", and next Eros the god of love. Hesiod goes on to say that Gaia brought forth her equal Uranus (Heaven, Sky) to "cover her on every side". Gaia also bore the Ourea (Mountains), and Pontus (Sea), "without sweet union of love" (i.e., with no father).

Afterwards with Uranus, her son, she gave birth to the Titans, as Hesiod tells it:

She lay with Heaven and bore deep-swirling Oceanus, Coeus and Crius and Hyperion and Iapetus, Theia and Rhea, Themis and Mnemosyne and gold-crowned Phoebe and lovely Tethys. After them was born Cronos (Cronus) the wily, youngest and most terrible of her children, and he hated his lusty sire.

According to Hesiod, Gaia conceived further offspring with her son, Uranus, first the giant one-eyed Cyclopes: Brontes ("Thunder"), Steropes ("Lightning"), and Arges ("Bright"); then the Hecatonchires: Cottus, Briareos, and Gyges, each with a hundred arms and fifty heads. As each of the Cyclopes and Hecatonchires were born, Uranus hid them in a secret place within Gaia, causing her great pain. So Gaia devised a plan. She created a grey flint (or adamantine) sickle. And Cronus used the sickle to castrate his father Uranus as he approached his mother, Gaia, to have sex with her. From Uranus' spilled blood, Gaia produced the Erinyes, the Giants, and the Meliae (ash-tree nymphs). From the testicles of Uranus in the sea came forth Aphrodite.

By her son, Pontus, Gaia bore the sea-deities Nereus, Thaumas, Phorcys, Ceto, and Eurybia.

Because Cronus had learned from Gaia and Uranus that he was destined to be overthrown by one of his children, he swallowed each of the children born to him by his Titan older sister, Rhea. But when Rhea was pregnant with her youngest child, Zeus, she sought help from Gaia and Uranus. When Zeus was born, Rhea gave Cronus a stone wrapped in swaddling-clothes in his place, which Cronus swallowed, and Gaia took the child into her care.

With the help of Gaia's advice, Zeus defeated the Titans. But afterwards, Gaia, in union with Tartarus, bore the youngest of her sons Typhon, who would be the last challenge to the authority of Zeus.