The Knights were not very popular with the town guards, who considered them to be a club of Farwil's drinking partners. The local guards complain that anytime something happens the Knights of the Thorn are nowhere to be found, or how they must put up with their boasts and insults since Farwil Indarys is the count's son.
Though the Knights boast of many battles and victories, prior to entering the Cheydinhal Oblivion Gate they had little to no fighting experience.
When an Oblivion Gate opened outside the doors of their Lodge, Farwil seized the opportunity to prove to the city guards that his knights were brave and courageous. So the Knights rushed into the gate without asking for help from the city guards. When they entered they quickly decided to launch a direct assault. This proved disastrous as most of the knights were slain by the first wave of Daedra and more dying in the second. Only Farwil Indarys and Bremman Senyan were able to survive the attacks, but could not escape due to the numbers and the injuries they had.
While traveling to gather Allies for Bruma the Hero of Kvatch came to Cheydinnhal, the Count's son, along with his Knights of the Thorn, had been inside for several days and nobody had seen or heard from them. It had gotten to the point that the count had offered a reward to the rescue or confirmed death of his son. The Hero entered the gate to shut it down and to discover the fate of the missing knights. Farwil and Bremman were still alive when the Hero reached them. Farwil, now believing the numbers to be more in their favor will state they can only go forward and continue the battle to reach the Sigil Stone and close the gate. Having no other way to go Bremman and the Hero must follow.
If Farwil survives the Oblivion gate, talk to him to become an honorary member of the Knights. If he doesn't live the Count may do the same.
All members of the Thorn wear the enchanted Knights of the Thorn Medallion, along with a specially embossed steel Knights of the Thorn Shield. All members also use a full compliment of steel armor with long swords.
In Hale, a former member of the Knights of the Thorn, Pyke, asks you to retrieve his Knights of the Thorn Medallion from the Grummite lair - Fetid Grove in the side quest, To Help A Hero. If you do, you are rewarded with the Thorn Shield, with leveled fortify block and reflect spell enchantments.
Only the Honorary Knight rank can be earned by the Hero of Kvatch.