CRONUS AND RHEA
This is pretty much where the big chunk of greek mythology starts, with Cronus and Rhea.
Cronus was the Titan of time and the ages. He is also the father of 6 of the Olympian Gods
Rhea was the Titan of female fertility, motherhood, and generation. She is also the mother of 6 of the Olympian Gods
So this is how the story goes in brief.
Cronus and his brothers had over thrown their dad Ouranos, and out of fear of having the same thing happen to him Cronus decided he would just eat his kids. So every time Rhea would have a baby, she would bring it to Cronus to show, and he would pick it up and eat the baby whole, but because the babies where Gods they where immortal and there for could not die and gre inside their dad Cronus. Hestia, Demeter, Hera, Hades, and Posidon where all born and eaten by their dad Cronus. Rhea gave birth to Zues and this changed everything. Rhea knowing that the second she presented the new baby to Cronus he would just pick the baby and eat it. Rhea decided instead to wrap a rock in a blanket it and present it to Cronus. Cronus was presented the "baby" and immeditaly picked it up and ate it. Now Rhea had Zues safe and hid him in the mountains to raise him.