Founding of Guardia
Era: 1 A.D.
Little is known about the founding of the Kingdom of Guardia, aside from the fact that the new kingdom felt it necessary to alter the calendar to reflect their establishment. That this event was accepted suggests that the founding was a huge and important event. It's thus likely that Guardia was a large civilization and empire at the time, carrying the fragile crux of civilization, rather than a petty warrior state that declared itself ruler. History is written by the winners, however, and the true nature of the founding remains an enigma.
The Frozen Flame was stated to have been kept by a northern kingdom, and if this refers to Guardia, perhaps the artifact granted the original Guardians enough power to establish a central kingdom around this time.