Wilhuff Tarkin

Grand Moff Wilhuff Tarkin is the secondary antagonist in Star Wars: Episode IV: a New Hope.  He is a high ranking moff in the Galactic Empire. He had a very high position in the Empire, before he was killed when the Rebel Alliance blew up the Death Star. He is portrayed by Peter Cushing in A New Hope, and voiced by Stephen Stanton in Star Wars: The Clone Wars and Star Wars Rebels.

Personality
Like Palpatine. Tarkin is Cruel, Cunning and ambitious. His only two goals are to destroy the Rebel Alliance, and one day take complete control of The Empire.

Revenge of the Sith
Tarkin was present with the Emperor, Palpatine and his apprentice Darth Vader who were overseeing the construction of the Death Star.

A New Hope
Tarkin became in full charge of the Death Star and determined to use its destructive power to destroy the Rebellion. However in order to find their secret base, he needed Princess Leia Organa to give the location of the Rebel Base but refused to speak. He decide to use some persuasion by threatening use the Death Star to destroy Leia's home planet, Alderaan. This made her give away the location of the Rebel Base, Dantooine. (apparently she was lying since the Rebel base on Dantooine was deserted) Even though she gave in, Tarkin still went ahead in destroying her home world and gave the order to fire, killing millions of lives.

When the crew and passengers of the Millennium Falcon were captured and attempted to rescue the princess, Tarkin ordered all sections on the alert and have Darth Vader to assure they do not escape. However they did escape, except Obi-Wan Kenobi who was killed by his former apprentice. Little did they know, the Imperials placed a homing beacon on their ship. Tarkin felt uneasy about letting them go because they were taking an extreme risk but knew it was the only way they could find the Rebel Base.

As the Rebel opened an attack on the Death Star, Tarkin had the station prepared for firing. Despite being warned of a dangerous chance that the Rebels may succeed, he denied any arrangements for evacuations and proceeded with the mission in hand. Unfortunately his poor judgement would be the death of him, when Luke Skywalker fired two proton torpedoes down one of the Death Star's ventilation shafts which led to the reactor system. Then just moments before firing, he was killed along with the Death Star's destruction.

Star Wars Rebels
In the pilot episode Spark of Rebellion, Tarkin is mentioned twice by the Rebels. First by Sabine when she explains to Ezra why farm locals call their home town Tarkintown, because he was responsible for kicking farmers of their farms when the Empire wanted their lands and anyone who tried to fight back got arrested for treason. As a resault they named Tarkintown after Grand Moff Tarkin himself.

Tarkin is mentioned again by Hera when she tells the commander of an Imperial Transport ship that they got paid by him for the bounty of a Wookiee Prisoner: as part of a plan to get on board and rescue Wookiee prisoners.

In the episode "Call to Action", Tarkin made a personal visit to Lothal to deal with the ongoing rebel cell after numerous failed attempts by Agent Kallus, Minister Tua and The Inquisitor, and upon his arrival immediately reprimanded them for their ongoing failures. Despite Minister Tua's claims that the leader of the Rebels was a Jedi, Tarkin chastised her for this belief as from his point of view, the Jedi were all dead and he intended to seek out this "criminal" and show that he was not what he claimed to be.

To ensure better results, Tarkin had The Inquisitor execute Cumberlayne Aresko and Myles Grint, illustrating that their weakness in the eyes of the public inspired hope and could threaten the stability of the Empire. His demonstration proved effective as it prompted the Inquisitor and Kallus to successfully capture Kanan Jarrus at an imperial communication tower. Tarkin arrived in person at the tower to bring the Rebel into custody and interrogate him, there he ordered his men to destroy the tower to prevent the Rebels from broadcasting their message to the public.

Upon returning to his ship, Tarkin began Kanan's interrogation by torturing him with help from the Inquisitor and Agent Kallus but all their attempts to make him talk led to no avail. For a further and more effecting alternative to make the Jedi talk, Tarkin took Kanan to Mustafar where he would be tortured even more, even to death. However, Kanan was rescued by his fellow and other Rebel cells which resulted in the loss Tarkin's ship, the Sovereign. Tarkin escaped the destruction of his ship and returned to Lothal where Agent Kallus informed him of some unrest all over the planet. Tarkin was at least concern about this matter as the Emperor had sent an alternative solution, Darth Vader.

Links

http://www.starwars.com/databank/tarkin