The Thirty Year Siege of Dwarfurt is generally considered the beginning of the end for a unified empire. The costly siege lead to the deaths of many Imperial soldiers, and extreme taxation levied on many of its peoples.
Al'Mudin, a mysterious prophet from some far-off and unknown land, began suddenly to preach in Nordradania. He preached in opposition to the official gods of the Reymal Empire, teaching instead the doctrines of a new deity: KOL. This repudiation of other gods, particularly the Emperor and his family, lead to his eventual martyrdom and would instigate the Rebellion of Twelve Kings.
The Prophet Al'Mudin was martyred after his preaching against the gods of the Empire reached the ears of a local imperial legate. He was burned at the stake on the Burned Rock, within sight of the fortress of Caer Luen.
Following the martyrdom of Al'Mudin, the twelve ancient northern kingdoms rose in revolt against the Reymal Empire.
On the verge of collapse and unable to bring the northern rebels to heel, the Reymal Empire was forced to concede independence to the North, with the March Lords acting as intermediaries.