Gaea

Gaea (Ancient Greek: Γαια), also spelled as Gaia or known as Ge (Ancient Greek: Γη), was the Greek primordial goddess of the earth. In Roman mythology, Gaea was equated with the goddess Terra Mater, who was also known as Tellus. Gaea was one of the first beings to emerge after the creation of the universe shortly after Chaos came into existence. Thus, Gaea had no parents but she was known as the "Great Mother" or "Mother Earth" since all beings of the earth were descended from her.

Overthrow of Uranus
After Gaea birthed the Hecatoncheires and the Cyclopes, Uranus locked them within Tartarus, causing Gaea great pain since they were her children. Gaea created a sickle made of the hardest material within the earth and asked her six Titan sons if they would overthrow their father. Five of them cowered in fear but Cronus took the sickle and agreed to help his mother. When his father came to lay with his mother, four of Cronus' brothers grapped onto their father in the four corners of the earth while Cronus castrated their father and threw his genitals into the sea. Cronus then became the ruler of the earth, skies, and Underworld.

Titanomachy
Cronus did not release his elder brothers from their Tartarean prison like he had promised he would to his mother so Gaea became angry with him. Cronus had heard of a prophecy that told that he would be overthrown by one of his children so, when each of his children were born, he swallowed them whole.

Rhea, the wife of Cronus, went to Gaea for help because she didn't want all of her children swallowed by her husband. Gaea instructed Rhea to give Cronus a rock swaddled in baby cloths to swallow instead of their sixth and final child. Rhea did as her mother instructed her and Zeus was raised in a cave, hidden from his father.

Zeus grew up to overthrow his father and released the Hecatoncheires and Cyclopes from their prison. However, Zeus imprisoned the Titan sons of Gaea, which made her dislike Zeus and want to dethrone him.

Gigantomachy
In an attempt to overthrow Zeus and the Olympians, Gaea sent her sons, the Gigantes, to attack the Olympians. Although there were many battles and fights, the Gigantes were defeated and Gaea's attempt to overthrow Zeus was unsuccessful.

Typhon
In one last attempt to overthrow Zeus, Gaea consorted with Tartarus and gave birth to Typhon, a monstrous giant. The gods ran away in fear but Typhon was eventually struck down with a thunderbolt and trapped under a mountain.