"I am to join General Tullius in the final attack on Windhelm, putting an end to the Stormcloak rebellion, once and for all."
Walkthrough
The Battle for Windhelm is the final Imperial Legion quest, ordered by General Tullius, who wishes to take over the city of Windhelm to find Ulfric Stormcloak and force him to submit.
After an inspirational speech by General Tullius, you fight through waves of Stormcloak defenders along with the legionnaires. The Palace of Kings is then raided, where Ulfric and his right-hand man Galmar Stone-Fist await you. Once Ulfric is defeated, he will request that the player be the one to kill him, as it would "Make for a better song," although you can refuse and allow General Tullius to strike the final blow.
After Ulfric and Galmar are defeated, General Tullius will reward you with a leveled sword which is different depending on the player's level. Upon retuning to Windhelm, Brunwulf Free-Winter will become the Jarl and will offer you the title Thane of Eastmarch as well as the opportunity to buy Hjerim, the player house availabe in Windhelm (12,000). At this point the city is now Imperial, thus the Stormcloak guards are replaced by Imperial Soldiers.
Trivia
During this battle, Stormcloak Soldiers will keep spawning if you stay in one area too long.
After Ulfric has just been killed is a good time to loot the palace if desired. A room upstairs via the first door on the left when you enter the palace is filled with the Stormcloak-aligned Jarls and their housecarls, many of which are unkillable (but not all).
After General Tullius is done making his speech, both he and Legate Rikke will leave, but the group of imperial soldiers will not.
It is impossible to betray General Tullius at this point, he cannot be killed.
Once killed, the bodies of Stormcloaks de-spawn almost instantly, making looting them very difficult.
It is possible for a dragon to spawn during the battle outside the Palace.
Even if not completing the Main Quest Ulfric will call the player "Dragonborn" regardless if he or she did complete the storyline or didn't
PC 360 PS3 The option to buy and upgrade Hjerim will not be in the speech list. This only happens in the same sitting as killing Ulfric. Saving and resetting the game will fix this.
PS3 PC If a dragon appears while Rikke is telling you to meet up with Tullius, your quest may glitch and keep directing you to her.
PC 360 PS3 Occasionally, after Ulfric and Galmar have been killed, the replacement Jarl (Brunwulf Free-Winter) will not spawn inside of the Palace of the Kings. Neither waiting for several game days nor leaving and returning to Windhelm have solved this problem. This makes purchasing Hjerim impossible as the Jarl will not be around to tell you how to become Thane and his aid does not have a dialogue option to purchase the home.
PC 360 PS3 When entering the Palace of the Kings, General Tullius and Legate Rikke will be attacked by Windhelm guards, which slowly wear them down-preventing Tullius from talking to Ulfric, which causes you to remain frozen in place while they are attacked. Loading to a previous save will not help this. Bring up the console with "~", click on a guard and type "kill", then hit Enter. Repeat for the other one. This will enable the dialogue to occur. After Ulfric's execution, once you go outside the Imperials will be finishing up the rest of the Windhelm Guard, so the two would have ended up dead anyway.
PS3 PC 360 Sometimes during the battle with Ulfric and Galmar, both enemies are still tagged as essential, and both of your allies just stand around after making their pre-fight speech. If this happens, you are stuck in the Palace of Kings with two unkillable enemies and two NPCs. Loading an earlier save does not prevent this from happening, and the console doesn't help either. There is no known fix for this bug.
FIX - problem can be solved via console. To make Ulfric and Galmar killable, type (without quotes): "setessential 0001414D 0" (that's for Ulfric) and "setessential 00014128 0" (for Galmar). That will make them mortal and quest will be completed.
No, this does not work; Ulfric and Galmar are immortal even after using these commands. To kill Ulfric, add the following lines to Skyrim.ini: [GamePlay] bEssentialTakeNoDamage=0 Ulfric is now killable after restarting the game (though you may have to heal him first if he's already kneeling). Remember to remove the ini value afterwards to avoid killing other essential NPCs.
This has also been patched for the XBOX 360.
PS3 In some instances, there will be no Stormcloak soldiers stationed inside of Windhelm-and the city will be empty with the exception of a few guards. Not even Rikke or Tullius and their forces even spawn inside of Windhelm. The Above glitch also happened, with Galmar chasing me out soon after I killed Ulfric.
PC 360 PS3 Ulfric and Galmar's bodies may not disappear from the Palace of Kings, even when Brunwulf Free-Winter is Jarl.
PS3 PC 360 Sometimes you will not receive General Tullius' sword, you may still finish the quest but you will not receive the sword. This is because the sword you get from Tullius, is same that you got, if you kill Ulfric yourself. Sword is a leveled sword that absorbs health.
PS3 PC 360 Sometimes Hadvar will glitch and follow you everywhere. Reload the game to solve this issue.
If you decide to loot too early an imperial guard may follow you, causing you too not be able to fast travel anywhere. Run out of the city and past the stables and constantly check your map for fast travel availability. (Upon returning you may pay the bounty)
360 If you complete the quest before doing "Blood on the Ice" this may cause the guard you have to receive permission from not to be there.
PS3 PC 360 When you go to meet up with soldiers, some may already be slain.
PC 360 PS3 Days after the Battle for Windhelm, some people will be sitting at the long table in the Palace. If you engage in dialogue, some of them will act as if they were still where they belong, the Rift, Markarth etc. saying stuff like "If you need a drink, go to [Inn in their homecity]"
PC 360 PS3 Right after you get into the Palace of Kings and defeat Ulfric, your game has a possibitity to go into third person mode (which there is yet to be a fix for it)