The Ash Guard is a secret organization formed after the signing of the White-Gold Concordat that is devoted to protection of the Empire of Tamriel. Formed by Thaddeus Grailin, the Count of Kvatch, the Ash Guard seeks to safeguard the Empire from a variety of threats, both internal and external. They do this in the hopes of returning the Empire to its former glory. While the Ash Guard fights a number of enemies, they consider the Thalmor to be their primary foe.
Following the end of the Great War with the Aldmeri Dominion there were many that did not want peace. These individuals had suffered terribly during the war at the hands of the Thalmor, often having been personally wronged, or having lost loved ones. As a result many objected to the White-Gold Concordat, and wanted to continue to fight the Thalmor.
Others were dissatisfied for a different reason. They saw what the Great War and the White-Gold Concordat had done to the Empire. The Empire, which had once been strong was now a shadoiw of its former self, and it often bowed to the wishes of the Thalmor in order to avoid war. These individuals saw the Empire losing its soul, and heading gradually towards ruin.
Among those who belonged to both groups was Thaddeus Grailin, the Count of Kvatch. Thaddeus had lost his brother, and his brother's family to the Thalmor. Furthermore he realized that the if the empire continued to give ground to the Thalmor, and allow them to corrupt the politics and values of the Empire, it would eventually collapse.
Determined not to see this happen, the Count gathered support from others that wished to continue resisting the Thalmor, and formed a secret organization, the Ash Guard. Thaddeus proved himself skilled in matters of politics, business and espionage. On the surface Thaddeus was one of the Thalmor's biggest supporters within the Empire, but secretly he sought to undermine them at every turn. Under his leadership the Ash Guard grew, becoming better organized, funded and equipped. The ash Guard had agents and informants throughout Tamriel. Thaddeus even managed to cultivate assets within the Aldermi Dominion itself. In order to protect his identity Thaddeus took the codename Thorn while acting in his secret role as the head of the Ash Guard.
While the Ash Guard managed to remain a secret to most throughout the Empire, the Thalmor slowly became aware of this covert group that was attempting to foil their endevours. They chose not to bring the group to the attention of the Empire, as they felt concern that public knowledge of the group might inspire others within the empire to join it. Instead they used their right to travel through the Empire's territory to hunt down Talos worshippers in order to fight a covert war against the group, much like they had with the Blades. While the Thalmor were moderately successful, the scope and internal organization of the Ash Guard escaped them. This lack of knowledge allowed the Ash Guard to continue its work even with the pressure from the Thalmor.
During the Ash Guard's secret activities Thaddeus became aware of numerous other forces at work in the world. These ranged from dangerous, unnatural creatures to deadly organizations and cults. with the empire in its weakened state these forces posed almost as much a threat to it as the Thalmor did. Thaddeus decided from then on that the Ash Guard's purpose would be to secretly protect the Empire from all potential threats, though the Thalmor would still remain a priority.