Elmar of House Hudor reigned for 54 years, but in the latter decade, fading mental acuity meant that a lot of the power was taken by the highest ranking military general, a member of House Foath called Lorss. In 1090, Lorss declared himself Elmar's successor, claiming that the Emperor had done so personally in a moment of lucidity, and when Elmar finally died in 1095 at the age of 96, Lorss demanded that the Imperial Houses ratify his succession.
Elmar's step-son, Calix, challenged this claim, insisting that it was Elmar's intentions to keep the Imperial Throne in House Hudor, and began gathering troops at his home territory near Ashris. Lorss summoned the Imperial Army and marched out to face this challenger.
Whilst Lorss was out of the capital, Domitius, a high ranking member of Elmar's court took the opportunity, and using his control of the Palace Guard and his own House's troops, declared himself Emperor in Lorss' absence. Faced with two challengers, Lorss established himself in Arall and began strategic planning to regain control.
The Empire was now firmly split between three contenders. Calix controlled most of the north-eastern part of the Empire, Lorss the south, and Domitius had the capital and the west. Lorss had the allegiance of the bulk of the Imperial Army, but Calix had secured a substantial number of House forces, and Domitius' control of the capital gave him unparalleled economic and political authority.
For three years very little changed, aside from almost constant skirmishes between the three factions, until in 1098, when Domitius was assassinated by members of the Palace Guard, who had finally been convinced by Lorss that his succession was valid. With control of the Imperial Capital in Lorss' hands, it was only a matter of time before Calix was defeated, and in late 1098, Lorss managed to bring Calix to battle, and he was killed.
With the pretenders removed, Lorss was finally ratified by the Imperial Houses, and took his place on the Imperial Throne.