Who is Cronos from Theogony and Works and Days and what is their importance?

Cronos is the son of Heaven and Earth, and Zeus' father. He avenges his brothers that Heaven hates and hides in a secret place in Earth by cutting off his father's members. Cronos marries Rhea, but when he learns from Heaven and Earth and he will be overcome by his own son, Cronos swallows each of his children as they exit Rhea's womb. His children with Rhea are Hestia, Demeter, Hera, Hades, Earth-Shaker and Zeus. Rhea convinces Earth to assist her in tricking Cronos when Zeus is born. Earth hides Zeus and presents Cronos with a rock wrapped in swaddling clothes. Cronos is fooled and swallows the rock. Earth raises Zeus, and once he is grown and strong, Zeus vanquishes Cronos. Cronos then vomits up his children, beginning with the rock that he believed was Zeus.