Talos

Talos, known as Tiber Septim, Ysmir, Dragonborn, and heir to the Seat of Sundered Kings, was, and arguably still is, the greatest hero-god of Mankind. Talos is worshipped as the protector and patron of just rulership and civil society.

Background
Tiber Septim conquered all of Tamriel and began the Third Era, as well the Third Empire, renowned to be the Septim Dynasty. Prior to his death he is believed to have ascended to godhood as the God of Man and War. Less prominent sects, such as the Talos Cult, were inspired by his apotheosis.

Talos, Ysmir, or Dragon of the North (a name given by the Greybeards of High Hrothgar to accompany his birth as Dragonborn) is a patron of questing heroes. He is referred to as the One in the phrase "The Eight and the One", as there were originally only Eight Divines before Tiber Septim ascended to godhood.

Fourth Era
During the Fourth Era, a war broke out between the Aldmeri Dominion and the Mede Empire, and this war came to be called the Great War which forced all races to take at least some part in it. The war concluded with the signing of the White-Gold Concordat. Two provisions in the treaty had serious impacts on what remained of the Empire, but one of the terms banned the worship of Talos. This allowed the Aldmeri Dominion (whose agents within Skyrim are known as Thalmor) to stamp out Talos worship and worshippers throughout the Empire. The banning of Talos worship soon produced the Stormcloak Rebellion in Skyrim, where the effects of the ban were most felt. If the Stormcloaks manage to win the Civil War, Talos worship will be returned to Skyrim and a shrine to him will be added in the Temple of the Divines in Solitude.