By 24PC Emperor Otto of the Holy Sigmarite Empire was becoming increasingly unwell. After reigning for 24 years the Emperor was now 56 years old and suffering from gout. Otto had two sons, Otto and Karl, aged 23 and 20, both born after the Empire was founded and having no ties to their old world. Otto, the older of the two boys stood to inherit the title when his father died, but a new force in Empire politics almost succeeded in thwarting that succession.
Karl, being no royal heir, was educated in the ways of religion by the sigmarite priest Ulfius, who, in 19PC had founded the independent church of Sigmar in Palurin, taking on the title of Grand Theogonist. This initially provoked some outraeg, but Ulfius's supporters succeeded in quashing most objections and Emperor Otto granted approval, if grudgingly, to the church in 21PC.
The church's influence was strongest in the north, particularly Sigmarheim, while the south was decidedly less pious. Sick of the endless puritan sigmarite litanies at home, in 22PC Otto moved his court to Hellveg in the Nimarn Valley, clearly signalling that the church was tolerated rather than supported.
Ulfius (now Ulfius the 1st) wanted more than mere tolerance to religious belief. He wasnted a devote state where the church's teachings not only influenced law, but were law. These thoughts of a holy theocracy with church and emperor standing side by side for the good of the people, acting as one, Ulfius passed on to Karl Alptraum, Emperor Otto's 2nd son.
When the old Emperor died suddenly in 24PC Ulfius moved swiftly to take control of the nation through his puppet Karl. Declaring Otto II a heretic of little faith, Ulfius declared that Karl should rightly succeed his father and ascend to the throne of the Empire. Civil war was now inevitable.
Ulfius managed to raise a large army of mostly peasants and fanatical sigmarites to his banner, as well as one or two of the more devout knightly orders. Otto II meanwhile retained control of much of the Empire's standing army. For months only skirmishes occurred until finally in late summer 24PC the two main armies clashed on the banks of the Nimarn in the Battle of the Marshes.
Ulfius tried to ambush Otto's more professional army by creeping across the Nimarn through a swamp. The two armies had been shadowing each other for days prior to the battle but Otto would not give battle on ground not to his liking. Frustrated, Ulfius sent across his army in the early morning mist, and as the sun rose battle began.
Early on in the battle misfortune struck the sigmarite army. Karl, present riding a pegasus as an inspiration to the men, was struck by two chance arrows and killed. As word of this passed through the sigmarite ranks the enraged army began to surge forward. Hampered by the swamp the infantry didn't get very far, but the elite cavalry broke ranks and ran headlong into the Alptraum army's elite greatswords. Alarmed by this lone charge Ulfius tried to lend his support, but his mighty war altar was at that moment pinned in place by a counter charge by Otto's elite cavalry, led by his trusted Templar Grand Master Gerd Von Arnheim.
Without support the sigmarite cavalry was annihilated, while Ulfius looked on. On the sigmarite left flank meanwhile a late arriving unit of cavalry began charging through the marshes, causing dismay in the sigmarite lines. In the centre the flagellants had managed to destroy and rout Otto's state troops, but once again the elite greatswords turned to finish the fanatics.
Although Von Arnheim was slain by Ulfius, with his elite cavalry destroyed and his lines in disarray from the flank charge delivered by Otto's cavalry, the first Grand Theogonist of the Holy Sigmarite Empire knew the battle was lost. His army broke and within two days Ulfius submitted himself to Otto II's mercy, recognising him as the true heir to the throne.
Otto spared the priest's life, banishing him from the Empire and, in an attempt to heal the wounds of the war, he returned the court to Sigmarheim and began construction of its cathedral as a sign of the union of church and state.