During this time, seas that turned to ice provided passage to Eorzea and subsequently allowed an influx of foreign fauna to her shores. This in turn brought the hunting tribes which subsisted upon them, the modern descendants of whom are today known as the Miqo'te.
Foreign fauna migrated to Eorzea followed by hunting tribes—the ancestors of the Miqo'te. The Sanctum of the Twelve dates back to this this time period.
This age in Hyadelyn's history is almost equivalent to the real world's Ice Age.