A single undead walked from his place of rest completely alone and without memory of his past life. Exploring the crypt that protected his remains for so long, he eventually saw himself ready to come out into the world that had long moved past him. Wandering aimlessly with only fate guiding him, he stumbled upon a village in the middle of being raided. Feeling compelled to intervene, he took the village for himself to command as new heroes flooded into the world to slaughter the demonic races who were left cornered by the races of the light. In that conquest of that one tiny settlement, so started the Rebellion of the Monsters.
--- Introduction of "The History of the Kingdom of Monsters" by Bardos the Mad