Tarkin served as a religious figure within the Aquilaean faith and held a position on the Aquilaean Council during the time that King Kayos reigned. A significant moment for him was his attendance at a Council session focused on the potential for war between his homeworld of Aquilae and the Emperor known as Cos Dashit. Tarkin, along with the other Council members, felt that a full-scale war was improbable. He considered the proposal put forth by General Luke Skywalker, which involved creating a resistance force to challenge the Emperor, to be somewhat radical.
The initial appearance of Tarkin was in the 1974 rough draft for what became A New Hope, where it was the title of the "Grande Mouff" in the Aquilean religion. This early story, spanning 132 pages, featured him with only one line of dialogue, and he was portrayed as wearing a long, dark robe and speaking in a shrill, unsteady voice. When the first Star Wars film was finalized, the character of Tarkin evolved into Grand Moff Wilhuff Tarkin, an Imperial human governor.
In 2013, Dark Horse Comics released a comic book version of George Lucas's original rough draft, titled The Star Wars. Tarkin, along with his single line, is included in the first issue of this adaptation.