House Xeduus was one of the eleven Imperial Houses in the Shirr'haim and were at one point in contention for the Imperial throne. Despite their efforts they were thwarted by the current Mandragora Empress, and were discredited in a number of scandals, including one of their number revealed as a Hellbinder.
In order to bolster their resources, as well as add to their holdings, the House looked at how it could expand beyond Lonaraban - and looked to Volkrania. To Mandragora eyes, Volkrania was ripe for conquest. Mandragora spies subverted from other Houses spoke of how Volkrania was weakened from the Orcgate War, and had no nearby allies that could easily come to its aid in war. The plans were made, and they were ambitious: House Xeduus was to seize control of Volkrania and use its resources to finance their efforts to take the Imperial Throne. One out-of- favour Imperial House managing to seize control of a country? Their opponents in the Senate would be crushed and swept away!
Xeduus Matriarchs began subverting senior army and navy officers to their cause and that of their House. House Xeduus already had strong links within the military and were able to secure the aid of three Wings of the Imperial Army, including their support corps. Scouting parties and members of the Dark Seed were secretly dispatched to Erilya, their directive to begin the Battle for the Shadows. The Cult of the Dragon was also founded at this time.
During the the Purge of Fire
Whilst the Battle for the Shadows and Purge of Fire was taking place, a number of Houses were becoming disturbed at the lack of any communication from their own spies in Volkrania (most were killed early on by the Dark Seed as a matter of priority). House Xeduus had hoped to secure their position before anyone could interfere. Any ships leaving for Volkrania were boarded, searched and where possible sunk (or turned back) by those loyal to House Xeduus.
However, the Xeduus forces could not stop everyone. A Shrikeship managed to evade destruction and sped on the Spellwind toward Erilya; aboard was the Imperial spy Arthogannax. In possession of a powerful magic item that allowed him to scry, and be scryed upon, over great distances, he was well-versed in both human customs and life in Volkrania. He spent some time observing and investigating the Mandragora presence in Volkrania, knowing that he would be killed instantly if his secret was uncovered. After a near-disaster in Kratishold, he made his escape and managed to evade capture by Xeduus picket ships.
According to tales from Noble Caste Mandragora who arrived since the Purge of Fire, it is said that when Arthogannax presented his findings to the Shirr'haim, the chambers dissolved into anarchy as the treachery of House Xeduus was revealed. Only the presence of the Shirr'haim Guard prevented House Xeduus attempting to seize power then and there. The fact that House Xeduus had invaded Volkrania wasn't the issue, instead it was their treachery against the Shirr'haim - a political gamble that had backfired badly.
The debate about what to do with House Xeduus raged for over a day in the Shirr'haim building itself, as the Xeduus Matriarchs were placed under arrest for treason. Fighting broke out in the streets between the PeaceForcers and those loyal to Xeduus, and for the first time in 300 years, martial law was imposed on the city. Despite the high security, the Matriarchs were able to escape and their fate remains unknown.
The Accords of Volkraad are signed
It is not clear as to why the Mandragora sued for peace in Volkraad at the signing of the Accords of Volkraad, as few Mandragora choose to speak of it at any length. However, there is evidence of a pitched naval and land battle in the land near Kratishold. Many scholars believe that Imperial forces sent by the Shirr'haim engaged the Xeduus loyalists, routing them and preventing their escape. The presence of The Remnant, and their lack of numbers, reinforces this belief.
In Lonaraban, the Imperial manse of House Xeduus stands empty, awaiting a new owner. The House Xeduus Scions are gone, protected and in hiding by the few allies they have left, and the none know the fate of the Matriarchs. To all intents and purposes, Xeduus is a dead house, its memory only living on with The Remnant and those few House Xeduus Mandragora in hiding.