Demography
The Ancients are an ancient nomadic people who called themselves the Cetra, and were the first species to inhabit Gaia. Their culture's goal was to find the Promised Land, and they believed in living in harmony with the Planet. As such, they cultivated Gaia's life energy and fought and defeated the alien Jenova when it landed 2000 years prior to the events of Final Fantasy VII. Some time after the defeat of Jenova, some of the Cetra abandoned their close relationship with the Planet and their search for the Promised Land, and became the ancestors of modern day humans. Aerith Gainsborough was the last Ancient, although she was also of Human descent on her father's side.
Read more about this topic: Gaia (Final Fantasy VII)