Tarkin was a career officer and politician throughout the waning years of the Republic and the rise of the Empire. He shared in many of the ideals that Palpatine enforced following his rise to power, such as consolidation of power through aggressive expansion and the superiority of Humans over the galaxy's other races. He gained great favour with the Emperor and soon achieved the title of Grand Moff, taking control of the Empire's largest oversector region and becoming head of the Death Star Project. In 0 BBY when the Death Star had reached its peak operating efficiency, Tarkin attempted to persuade the captive Princess Leia Organa to divulge the location of the Rebel Alliance's headquarters by threatening to destroy Alderaan, her homeworld. When he thought that the princess had caved in and surrendered the Rebel base's whereabouts, Tarkin ordered Alderaan's destruction anyway as a demonstration of the Death Star's power.
During the Battle of Yavin, Tarkin was utterly convinced that the Rebel Alliance had no hope of defeating the Death Star, even when one of his lieutenants informed him that the battlestation did possess a weakness that the Rebel fighters would be capable of exploiting. Tarkin arrogantly dismissed the notion and refused to evacuate the station when the Empire was on the cusp of victory. In the end, Tarkin perished when Luke launched a proton torpedo salvo down the thermal exhaust port that linked to the station's main reactor, obliterating the station completely.