100k YA to approximately 500 YA
Goblins expanded quickly during the last ice age, as they deliberately selected themselves to become smaller and more numerous. Africa and Australia would be the only continents they would not reach. Goblins created cavernous warrens within the glaciers, often connected by long tunnels, which could grow to 100k individuals. There was a theoretical Goblin sovereign called the Erkling – but this was more of a religious position than a political one. The individual warrens pretty much governed themselves. The Goblin Empire was more a shared society than a political entity.
Goblins subsisted on hunting, both above and below the ice.
As the glaciers retreated, so did the Goblins. Some adapted their ways to underground, and such Goblins persisted in Europe into Historical times. Goblin warrens persisted in Greenland and Antarctica into modern times, though they were barely recognizable due to prolonged isolation.