as told by Hesiod (c. 800-700 BC) in Theogony [adapted from various translations]
Let us first invoke the Muses of the great and holy mountain of Helicon, who sing praises of Zeus and Hera and the other gods. One day they taught Hesiod glorious song while he was shepherding his lambs under holy Helicon . . . and bade me sing of the race of the blessed gods that exist eternally . . . .
Let us begin then with the Muses, the daughters of Zeus and Mnemosyne (Memory), who sing of all things in heaven and earth. When they honor someone. . . . they pour sweet dew on his tongue. All people look to that man, and when he passes through a group they greet him as a god with gentle reverence.
Hail, children of Zeus! Tell of the beginning when gods and earth came to be, and rivers and the boundless sea with its raging swell, and the gleaming stars, and wide heaven above; and how the gods were born of them, and how those gods divided their dignities and first took Olympus.
At the first, Chaos came into being, next wide-bosomed Gaea (Earth), dim Tartarus (below Earth and Hades) and Eros (Love), fairest of the deathless gods, who unnerves the limbs and overcomes the mind and wise counsels of all gods and men. From Chaos came forth Erebus (Darkness unfathomable where Death dwells) and black Night. From the union of Night and Erebus were born Aether (Air) and Day. Then though Night lay with none: Doom, Moira (Fate), Death, Sleep and the tribe of Dreams, Blame, painful Woe, the Hesperides (daughters of the evening) who guard the golden apples in the trees beyond the ocean, and Nemesis, Deceit and Friendship, and hateful Age and Strife.
And Earth first bore starry Heaven (Uranus), equal to herself, to cover her on every side, and to be an abiding place for the blessed gods. And Earth brought forth, without intercourse of love, the Hills, haunts of the goddess Nymphs, and Pontus the sea with his r1ing swell. And Earth lay with Heaven and bore their children the Titans: 6 sons and 6 daughters, Oceanus, Coeus, Crius, Hyperion (Sun), Iapetus, Theia, Rhea, Mnemosyne (Memory), Phoebe, Tethys. And last was born Cronus, the wily and most terrible of her children. And he hated his lusty sire.
Earth and Heaven had more sons, the three Cyclopes, overbearing Brontes and Steropes, stubborn-hearted Arges, who gave Zeus the thunder and made the thunderbolt. In all else were they like the gods, but for their one eye as big as a wheel set in the middle of their foreheads. Thus they were called Cyclopes (Wheel-eyed). Three other sons were born, each with 50 heads, from whose shoulders sprang 100 arms. Their stubborn strength was irresistible. Of all the children these were the most terrible. They were hated by their father from the first. He hid them away deep in the earth and would not let them come up into the light.
Vast Earth groaned within at the evil deeds of Heaven, and she thought a crafty wile. She made the element of grey flint and shaped a great sickle and then told her plan to her dear sons. "My children, gotten of a sinful father, if you will obey me, we should punish his vile outrages, for he first thought of doing shameful things." But fear seized them all except Cronus the wily, who took courage and answered his mother. "Mother, I will undertake to do this deed, for I do not reverence our father of evil name, for he first thought of doing shameful things."
When Heaven came, bringing on night and longing for love, he lay about Earth spreading himself full upon her. Cronus reached out from his ambush and castrated his father with the jagged sickle and cast the severed members behind him. From the bloody drops which Earth received, when the seasons moved round, she bore the Giants and the Nymphs and the strong Erinyes (Furies) who pursue and punish sinners. Their hair was writhing snakes and their eyes wept tears of blood. As the severed members of Uranus were swept away in the sea, the white foam that spread around them formed a lovely goddess whom men call Aphrodite (Venus), because she was born within the foam.
With the other Titans, Cronus liberated the brothers from Tartarus and they all made him their ruler. Then he hurled the Cyclopes back to Tartarus and married Rhea his sister. Because he was warned by Earth and Heaven that he would be overthrown by his son, he swallowed all the children Rhea bore: Hestia, Hera, Demeter, Hades, Poseidon. When Rhea was about to give birth to Zeus, she went to Crete and hid the infant there and substituted a stone wrapped in swaddling clothes, which Cronus swallowed. When Zeus grew up, he forced his father to release his swallowed brothers and sisters, and then released the brothers of Cronus from Tartarus. In return the Cyclopes gave Zeus the thunder and lightning by which he rules, and with which he and his brothers were able to defeat Cronus and the Titans and to establish the reign of the Olympians.
After Zeus' victory, the gods chose him to rule, and he divided and assigned their powers and privileges among them. According to various sources, he fathered many of the lesser gods, goddesses, and legendary mortal and immortal figures, from his relations with other goddesses and mortal women.
The Romans referred to Cronus as Saturn, and to Zeus as Jupiter.
The Fates (Moirae): Three women controlling destiny of man's life: Clotho--the spinner of the thread of life; Lachesis--the measurer; and Atropos--the inexorable, who cuts it.
The Furies (Erinyes): Also called Eumenides (Kindly spirits). Vengeance and eternal pursuit of murderers, perjurers, those disrespectful to parents: Alleco--she who rests not; Tisiphone--avenger of murder; and Megaera--the jealous one.
Nemesis--indignation, measures out happiness and misery; later punishes crimes, especially of the proud, arrogant.
Athene; Pallas Athena: Born directly from Zeus. He made Wisdom (Metis) his first wife but swallowed her before she could give birth to Athene, so that he could be her only parent. Athene sprang forth from the head of Zeus in full armour. Her origin is traced anthropologically from pre-Hellenic virgin war-like goddesses in Mycenaen culture. Adapted by the Greeks, she became patroness and defender of the Athenian state, personification of wisdom, protecting and guiding crafts, and fertility of animal and vegetable life, all for the well-being of the state.
The Muses, 9 of them, were the inspiring goddesses of song, and later seen as the divinities presiding over the different kinds of poetry (epic, tragedy, comedy) and the arts and sciences (history, astronomy).