The modern world has the knowledge about Ancient Greek gods and goddesses thanks to Greek poet Hesiod's The Theogony. It is a mythological poem which was composed c. 700 BC. Another source which reached us is Roman poet Ovid's (43 BC - AD 17/18) Metamorphoses. It is a chronicle which starts with the creation of the world and ends with a dedication to Juilius Ceaser. The epic poem contains around 250 myths!
In Greek mythology there is a huge number of gods and goddesses, however there are twelve major, so called Olympian gods. Without further ado, let's name and discuss each of the Twelve.
Zeus (Jupiter) is the youngest child of Cronus and Rhea. Cronus was the god of time i.e., calendars, seasons, and harvests. He had overthrown his tyrant father and became the leader god in his generation. Cronus, now afraid, that one day one of his own offspring will do the same to him, decided to get rid of his children. He ordered his wife Rhea to bring forward all of the children they had, and he devoured all of them. Rhea managed to fool Cronus and instead of her youngest child she gave him a huge stone, which the latter devoured without realizing what's happening. Zeus was hidden in a cave on the island of Crete, where he grew up. He eventually sought revenge and overthrew Cronus, cut his belly, and released his siblings. He then became the leading god in Greek mythology. Zeus now resides on the peak of mount Olympus, where he sits on his golden throne and rules over the world. One of Zeus's most known symbols is thunderbolt. He is revered as the allfather and chief of the gods.
Hera (Juno), the goddess of marriage, is Cronus and Rhea's daughter and Zeus's wife. After she was freed from her father, her mother took her to a faraway land where the latter was brought up. One day from the heights of Olympus Zeus noticed her and fell in love. He then kidnapped Hera and made her his wife. Hera is the goddess patroness who protects the inviolability of marriage and family. She is the one who protects mothers during childbirth. She is powerful and is above every other goddess. However she was always jealous of Zeus and his affairs. Hera often tried to get revenge from Zeus' lovers and children. Some of her symbols are peacock, cuckoo, and cow. Poseidon (Neptune) is the brother of Zeus, the god of seas and tidal waves. He resides in his own palace in the abyss of sea. He controls the seas, and the waves abide to the movements of his hands and his trident. His wife is the beautiful Amphitrite, whom he had kidnapped from her father Nereus, a wise prophet. A dolphin helped Poseidon kidnap the woman who enchanted him, and as a prize Poseidon placed him amongst the stars as the constellation Delphinus. His most known symbol is the trident; however other notable symbols are horse, bull and dolphin.
Demeter (Ceres) is the sister of Zeus. She is the goddess of fertility, agriculture, nature and seasons. She was mostly worshipped by farmers. Her and Zeus' daughter Persephone was abducted by Zeus' brother Hades, and taken to the dark and grim underworld. Demeter sought her daughter and after she found out that Zeus had given her daughter to Hades without her consent she was enraged. In her sorrow she left Olympus and the gods. She took a form of a mortal woman and shed tears of bitterness for a long time. The earth stopped growing, everything green withered, fields and gardens lost their fertility. Eventually Zeus sent his messenger Hermes to his brother's dreary kingdom. Hades agreed to let his wife visit her mother. In her joy Demeter brought back the fertility to the earth, and the flowers started growing again. However every year, for a certain period of time Persephone leaves her mother and returns to her husband, and in this period Demeter falls into bitter sorrow again. All of the nature grieves together with her until Persephone returns from the underworld.
Athena Pallas (Minerva) is Zeus' daughter, and the most favorite of his children. Zeus found out that Athena's mother Metis would give life to two children, a girl and a boy. The boy was foretold to have extraordinary powers and would be able to overthrow Zeus and take his place as the head of the gods and the leader of the world. To avoid such a terrible fate Zeus swallowed sleeping Metis. After some time Zeus was suffering from severe headaches. Zeus called his son Hephaestus and asked him to open up his head so that he can get rid of the headache. As soon as Hephaestus swung his axe and cut Zeus' skull, a powerful she-warrior jumped out of Zeus' head. She was in her full armor, holding her shield and spear. Athena is the patroness of heroes. She is the goddess of wisdom, reason, handicrafts and strategic warfare.
Apollon (Apollo) is the golden-haired god of light. He is the son of Zeus and Leto. Hera was furious with Leto, since the latter had an affair with Zeus. Leto had to flee and finally found a sanctuary on the island of Delos, where she gave birth to her twin children, Apollon and Artemis. Delos was an uninhabited island in the middle of the sea, there was no flora and no fauna, only the seagulls were flying around and squawking near the rocky hills of the island. When finally Apollon, the god of light was born, the whole island was enlightened. It felt that Delos was filled with gold. Everything started blooming and shining. Gods and goddesses gathered on Delos to celebrate the birth of Apollon. They treated him to ambrosia and nectar. Nature rejoiced together with everyone. Apollon is also regarded as the god of prophecy, inspiration, poetry and arts. Some of his most known symbols are lyre, laurel wreath and python. Artemis (Diana) is Apollon's twin sister, the huntress goddess of the Ancient Greek. Brother and sister are connected with bonds of friendship and eternal love. They love their mother just as much. Artemis, forever young, beautiful, takes care of every living thing on the earth; she takes care of the animals, both wild and domestic. Whenever she goes hunting, all of the nymphs start following her through the forest. Her aim is always flawless and no animal can escape her arrow. She is the patroness of hunt, virginity, archery, the moon, and all animals. Her symbols are moon, deer, cypress tree, and bow and arrow.
Ares (Mars) is the son of Zeus and Hera. He is the lover of Aphrodite the goddess of love and beauty. Some legends, however, portray her as Ares' wife. Ares is the god of war, bloodshed and violence. Zeus doesn't especially love his son. He would gladly throw Ares into the pits of Tartarus, if the latter wasn't his own son. The only thing that brings joy to Ares is bloodshed and severe battles. Yet, even though Ares is almighty and invincible, victory is not always beside him. It is not seldom for him to surrender to Zeus' warrior daughter Athena Pallas. Even if Ares' beautiful wife Aphrodite comes to his aid, she is instantly pierced by Athena's spear and returns to Olympus in tears. Some of the most common symbols of Ares are boar, serpent, spear, and shield.
Aphrodite (Venus) is the goddess of love, beauty and desire. There are two versions of her birth. One states that Aphrodite is the daughter of Zeus and Oceanid Dione, the other that she is the daughter of Uranus, and was born from sea foam. In some legends she is portrayed as the wife of Ares, in others as the wife of Hephaestus. She has control over hearts of both gods and humans. Thanks to this power she rules over the entire world. The only ones who aren't being affected by her charms are three goddesses: warrior Athena Pallas, Artemis, Hestia. She is the impersonation of godly beauty and imperishable youth. Her symbols are dove, bird, swan, and rose.
Hephaestus (Vulcan) is the god blacksmith and the patron of crafts; he is the god of fire and forge. He is the son of Zeus and Hera. He was born a crippled and weak child. Hera was furious with the child she bore and threw him away from Olympus to the world of mortals. He fell into the ocean, and the goddesses of sea started taking care of him. Hephaestus grew up ugly and a cripple, however he had mighty hands. He was furious with his mother for a long time. He forged a golden chair for Hera and sent it to Olympus as a gift to her. She was more than delighted with the golden chair, which was worthy only of the mother of all gods and humans. But, alas, as soon as she sat on it, she was wrapped with indestructible ties. None of the gods could help her out of this trap. They sent Hermes to bring Hephaestus to Olympus. Yet his pleas were unable to move the heart of the wounded child. It was Dionysus who was able to bring Hephaestus to Olympus after treating him to wine. Hephaestus was intoxicated with wine; he came back to Olympus, freed his mother from the golden trap and stayed on the mountain of gods amongst his brothers and sisters. Some of his symbols are fire, anvil, axe, donkey, hammer, tongs, and quail.
Hermes (Mercury) is the messenger of gods, god of commerce, thieves, eloquence and streets. He is the son of Zeus and the nymph Maia. He floats around the world in his winged sandals, and carries the messages of gods. He is the one who leads the souls of the dead to the underworld. Hermes has invented the numbers and alphabet. He is also revered by the thieves. The legends state that Hermes has stolen Zeus' scepter, Poseidon's trident, Apollo's golden bow and arrows, Ares' sword. His symbols are caduceus (staff entwined with two snakes), winged sandals and cap, stork, and tortoise (whose shell he used to invent the lyre).
Dionysus (Bacchus) is the god of wine, celebrations and ecstasy, patron of arts and theatre. He is the son of Zeus and the mortal Theban princess Semele. Zeus loved her so much that he swore on the River Styx to grant anything she wanted. The jealous Hera befriended Semele and told her to ask Zeus to stand in front of her in his true form. And so she did. When Zeus stood in front of her in his godly form, holding a bolt of lightning in his hand, the palace where Semele lived was instantly caught in uncontrollable fire. She left out a shriek and collapsed, her body started burning. Dying Semele gave birth to Dionysus. Yet he was too weak and close to death. Zeus didn't want to lose his son too. He sewed Dionysus into his thigh. Several months passed and Dionysus was born from Zeus. He is hence called the twice-born. Some of his symbols are grapevine, ivy, cup, tiger, panther, and pinecone.
It is worth mentioning that one of the Olympian goddesses was Hestia (Vesta), the goddess of hearth, sister of Zeus. She however stepped down and her position was given to Dionysus.
Another notable Olympian was Hades (Pluto) who however resided in the underworld kingdom of Tartarus. His position as an Olympian was given to Demeter.