The Great Kingdom arose from the Kingdom of Aerdy in -110 CY, when the Aerdi forces of Grand Prince Almor II defeated the Nyrondese in the Battle of a Fortnight's Length. Aerdy nearly doubled in size, and was thereafter known as the Great Kingdom, though its ruler still held the old national title and office of Grand Prince. Despite the new moniker, power in the new empire would not become truly centralized until 1 CY, when Grand Prince Nasran I declared universal peace throughout the land and took the title of Overking of the Great Kingdom of Aerdy.
In 586 CY, Ivid V, last Overking of the Great Kingdom, was rumored to be dead after the devastation of Rauxes, the nation's capital. This essentially brought an end to the Great Kingdom. Two successor nations, the United Kingdom of Ahlissa and the North Kingdom of Aerdy, now vie for control of the region.