User blog comment:Emperor Maximus/On the Civil War/@comment-50.159.28.95-20150406214248/@comment-1738746-20150408003055

Draevan13 is (somewhat) correct- the Empire was too busy fighting the War to help Markarth despite the Jarl's constant pleas for help. The Jarl instead turned to Ulfric for help, where Ulfric said he would help and if they won, the Temple of Talos would be restored. The Jarl naturally agreed and Ulfric's milita chased out the Forsworn. When the Empire finally decided to give a damn about Skyrim, they arrived to find Ulfric and his men at the door. He wouldn't let them return to their posts until they agreed to keep allowing the worship of Talos in the city. They agreed, got back to their posts, and when all was fine again they went back on their deal and imprisoned Ulfric and his men for I can't remember how many years (while in prison, this is where his father died).