Before the Great Cataclysm humanity was prospering, slowly colonizing the wilds, extracting resources out of the ground and claiming land for themselves.
After the Great Cataclysm has occured, humanity was thrown into dissaray: settlements fell to hordes of undead, armies couldn't stand up to the foe and scattered groups of humans were killed off either by monsters or the undead legions.
There seemed to be no hope untill a legendary warrior named Thorfinn with his rallied army of a thousand men held the line against the undead hordes where the present Grand Bastion stands.
They held them off for months untill makeshift defenses were set up by other survivor groups, marking The Grand Bastions founding. Since then the Bastion evolved into what it is today - a monument to humanity's resilience and unbreakable fighting spirit.
During present times, humanity is still holding the line against the tide of undead, slowly building up cities and villages after the border with Ashen Wastes was secured for the time being.
People are trying to find a way to stop this madness and finally kill Vorathul Nox-Kael, ending the endless tides of undead - but it is unknown if it's even possible.