Mendev as it is now began with the First Mendevian Crusade in 4622 AR. The crusade was launched to stem the tide of chaos flowing from the Worldwound. This crusade was launched by the faltering church of Aroden whose death was somehow linked to the formation of the Worldwound, they tried to use the crusade to whip the followers into a righteous frenzy. These crusades were to be led by the followers of Iomedae hungry for a righteous cause to fight for. As the thousands of pilgrim crusaders flooded up the Sellen River and across the Lake of Mists and Veils and into Mendev the crusader state was born.
This first crusade managed to push back the demonic hordes in short order and was deemed a success, the crusaders believed they had defeated their abyss-bound foes. And for almost a generation it seemed that they were right, the frontier with the Worldwound was quiet. When the demons struck back it was with a terrible vengeance causing the crusaders costly defeat after costly defeat, their worst lose being the crusader city of Drezen in 4638 AR which now lies well within the Worldwound. In light of their defeat a Second Mendevian Crusade was launched and since them two others have been launched with Mendev now in the middle of the Fourth Mendevian Crusade with little hope of achieving a complete victory the crusaders seem to have settled for merely containing the ever present threat