The Fourth Epoch is the Era in which Shiayar actually lived, with the establishment of the Holy Calendar as the turning point.
The Echo of History in Escarnia, where Shiayar resided, was the intersection of the Third Era and Fourth Epoch.
As for the First Era, even the Knowledge Holy Chalice knew little, for its Authority could only comprehend the present, while the First Era predated the birth of the Knowledge Holy Chalice.
The emblem of the Second Era, then, was the enlightenment of Arcane Arts and the establishment of the Wizard and Beastmaster Systems.
And also, the construction of the Black Tower.
Indeed, although the Supreme Black Tower, True Red Tower, and White Tower are collectively referred to as the "Three Towers Wizards" on the Western Continent today.
