The Nerevar Incarnate, the Dragonborn and far-star-marked Conqueror of Alduin, recognized the rapacity of his hired minion Hjornskar Head-Smasher, the Stormcloak Commander of the rebel army, who betrayed his liege lord Ulfric for the love of Veloth coin and declared Whiterun for himself after taking the city from the Imperials, he persuaded his Bladed Companions at Karthwasten that they should return to Whiterun and avenge the death of Jarl Balgruuf, the defilement of the city, and the slaughter of its citizens by both the red and blue factions. With this excuse to hide his own aspiration for the annexation of Skyrim to his Veloth Khanate, he moved his army toward Whiterun, reaching Whiterun hold even before it was known that he had set out. Upon his arrival in Whiterun, the oppressed people of that city opened its gates for the Dragonborn Nerevarine who shouted Hjornskar to death.

Having consolidated his hold over the central plains of Skyrim, the Dragonborn Khan of Velothistan's allied rulers of Markarth, Falkreath, and Riften (who owed their success to his patronage) threw their support behind the Dragonborn Khan. With all this accomplished, only two obstacles required removal before the Dragonborn Incarnate could be master of all Skyrim. One lay in the west, in Haafingar, where the ill-fated General Tullius, who commanded the remnants of the Skyrim legions, had proclaimed himself Duke of Solitude. The Elder Council in old Cyrod clamored for Tullius' immediate recall and execution after his perceived failure to stop the rebellion and allowing the Emperor to be assassinated on his watch. Facing disgrace and possible death, Tullius seized power as the Potentate of Haafingar Hold. The other obstacle lay in the east, in Eastmarch, where Jarl Ulfric Stormcloak, who also aspired to the Jagged Crown of Skyrim but was bereft of much of his rebel army when Hjornskar turned traitor, ruled in Windhelm.

Judging it dangerous to reveal himself as an enemy to both, the Dragonborn decided to attack Tullius and to deceive Ulfric. He wrote to the latter saying that since he had been exhorted by the general public to be the future High King and, by consent of his allies, made him his royal partner. Ulfric took these gestures to be sincere and even gave him a battalion of his own men-at-arms to aid the Dragonborn Khan in his attack upon Solitude. But as soon as he had defeated and slain Tullius and settled matters in the west, he returned to Whiterun, where he complained to his allies that Ulfric, scarcely grateful for honors received, had treacherously plotted to kill him. The Dragonborn presented Aldmeri intelligence reports to his allied Nord rulers, provided by his Thalmor lover Elenwen, that Ulfric was a Thalmor sleeper agent who instigated the rebellion to weaken both the Mede Empire and Skyrim for the benefit of Alinor. As a consequence, Ayden felt compelled to punish his partner's ingratitude and treachery. Then he marched off to attack Ulfric in Windhelm, where he deprived him of his authority and his life.