Orc tribes used to spread throughout the continent of Gashuk on Twilight World however after Nightfall their home was infested by a glowing blight of plants, who took over the whole continent over the next century forcing them to flee to Hadira bringing them into conflict with the humanoid races there and eventually an alliance to fight back the blight. The orc tribes are split between the worship of two ancient Dragons. Pythios the Red dragon of creation and Agoras the white dragon of destruction, their creation myth involves these two dragons fighting over this world and in the process creating the water and heat needed create life.
Before Nightfall froze the seas the orcs were proliferate raiders and pirates and the few tribes which have managed to get their hands on a Spelljammers have taken to pirating the void with their usual fierceness.