The Old Gatian Era is the semi-mythological time that existed before the founding of Aesedra by Ucto the First. According to what history survives, it was a time of chaos, where wizards and sorcerers openly ruled the land and it was magick, not alchemy that was the prime mystical force of the world.
According to religious tradition, humans came from elsewhere and populated the world between 500-1000 years before the founding of Aesedra. They arrived through the agency of magick and a struggle between the wizards and followers of The Five began, that ended with the victory of The Five and the founding of Aesedra.
In truth, next to nothing is known of this time, and it is shrouded in factual darkness and legend.