At some point in history, the kingdom was established on Westside Island, and clashed with the United Federation at some point. Eventually, it came to be ruled by King Nigel Acorn. While he ruled justly, the king made the mistake of trusting Dr. Eggman, who repaid his kindness by banishing him to the Special Zone. Eggman reigned in tyranny over the conquered kingdom for a unknown amount of time before being overthrown by the Freedom Fighters under Sally and Sonic the Hedgehog. The king was subsequently rescued and restored, and pledged his kingdom towards opposing the Eggman Empire. Most of the kingdom's holdings were apparently reclaimed following Eggman's defeat, but a unit of his Egg Army retained a foothold in the Metropolis Zone.