When Zeus decided to end the Golden Age with the great deluge, Deucalion and his wife, Pyrrha, were the only survivors. Prometheus told his son to build an ark, and thus they survived.
Once the deluge was over and the couple were on land again, Deucalion consulted an oracle of Themis about how to repopulate the earth. He was told to throw the bones of his mother behind his shoulder. Deucalion and Pyrrha understood the "mother" to be Gaia, the mother of all living things, and the "bones" to be rocks. They threw the rocks behind their shoulders and the stones formed people. Pyrrha's became women; Deucalion's became men.
Deucalion and Pyrrha had two children: Hellen and Protogenea