Message to Whiterun (Imperial)

Walkthrough
There is an equivalent quest if the Dragonborn joins the Stormcloaks. Note: You must have completed the quest Dragon Rising in the main quest before being able to complete this quest.

Deliver message to the Jarl of Whiterun
The city of Whiterun is of strategic value to both the Imperials and the Stormcloaks. After giving him the Jagged Crown, General Tullius decides that it is time the Jarl of Whiterun decided whose side he is on, and sends the Dragonborn to find out. He then instructs the Dragonborn to deliver a message to Jarl Balgruuf.

Wait for the Jarl's response
Travel to Whiterun and find Jarl Balgruuf inside Dragonsreach and deliver General Tullius's message. Jarl Balgruuf will then converse with Irileth and Proventus Avenicci for a brief period of time during this time you can freely roam around Dragonsreach, and he decides to side with the Imperials in the civil war.

Deliver axe to Jarl Ulfric
He will give you his War Axe, and ask you to deliver it to Ulfric Stormcloak in the Palace of the Kings located in Windhelm, to signify that there is to be war. Ulfric Stormcloak will tell you to return to Whiterun and give Jarl Balgruuf back his axe.

Return to Whiterun and warn the Jarl
Once you return, Jarl Balgruuf will not be surprised that Ulfric Stormcloak returned the axe, he has already requested that General Tullius dispatch Legionaries to help defend Whiterun.

Report to Legate Quentin Cipius
Legate Quentin Cipius will be in Dragonsreach after this happens, you will need to report to him.

Eine Nachricht für Weißlauf (Kaiserliche Legion)