Silent Ages
The Silent Ages traditionally refer to the years between the Fall of the Western Kalassarian Empire and the Fall of Bastion. Recent scholarship argue, however, that the age should be defined by the earliest evidence of the disappearance of magic from Thera, and tail-ended by its return, which does coincide with the Fall of Bastion.
This would put the earliest estimation of the Silent Ages to be from 435 AI to 1225 AI.