Once the heir apparent to the League of Ostermark, ever since he was a young boy, Stefan believed that his grandfather and father were worshippers of Chaos. Branded across the face as an infant with the Mark of Chaos, he bore the scars of this suspicion physically as well as mentally.
His family stripped of their titles and wealth, Stefan made a life for himself in the Empire's army. He was determined to prove his loyalty to the Empire, and had a fiery dedication to Sigmar. He loathed Chaos in all of its guises and was vehement that the Empire would be victorious against the warbands invading from the North. He was an educated man, and a veteran of the Great War Against Chaos, with a confidence and tone of command honed on bloody battlefields across the Empire.
During the course of his campaign to drive the Chaos warbands out of the lands of Talabecland, Ostland and Ostermark, Stefan won many great victories which led to his recognition by the Reiksmarshal and Emperor Magnus the Pious. Eventually, he uncovered a conspiracy whereby he found the current Elector Count of Ostermark was himself a Chaos Cultist and that he was responsible for falsly accusing of his father and grandfather of heresy, allowing him to take the title away from him. After the traitor's death, Magnus reinstated Stefan and the Von Kessel family back to their status.
- 1: Warhammer: Mark of Chaos