As a human governor presiding over the moon of Toshara, Thorden served the Galactic Empire during the Imperial Era. During the Galactic Civil War, Thorden came to the conclusion that the Alliance to Restore the Republic stood a chance of defeating the Empire, so he began making preparations for this potential eventuality.

Holding the position of governor, Thorden wielded considerable authority over the Galactic Empire's presence on Toshara, a moon. Thorden maintained an arrangement with the Pyke Syndicate, the most influential criminal enterprise operating on Toshara. However, Thorden's plan involved betraying Gorak Palas, the Pyke in charge of the syndicate's operations on the moon, enlisting the assistance of Tizlak Sharr, a Pyke who had already betrayed Palas.
In 3 ABY, Thorden, convinced that the Empire was likely to be defeated by the Alliance to Restore the Republic, initiated preparations to establish his own independent government on Toshara amidst the anticipated chaos. His resource acquisition efforts included attempting to obtain the coordinates for the fabled hidden moon known as Okala Five. Rumored to contain a staggering two point eight trillion tons of pure cyphrite ore, Thorden intended to utilize this resource to construct a powerful weapon. Thorden's prediction regarding the outcome of the Galactic Civil War proved accurate in 4 ABY, when the Battle of Endor plunged the Empire into disarray, leading to the death of the Emperor and the emergence of various dissenting factions, signaling the beginning of the Empire's downfall.
The coordinates to Okala Five were to be awarded as the top prize in a sabacc tournament. Because Imperial officials were barred from participating, Thorden dispatched Kay Vess, a skilled thief who had previously caused Thorden to lose his book-keeper, Bosnok, to secure victory in the tournament. In exchange, Thorden promised her a substantial sum of credits and resorted to blackmail, using fabricated credentials that would falsely portray her as an Imperial agent to the underworld, effectively ruining her reputation. However, Thorden never anticipated that Vess would actually win the tournament. The credits he provided her were rigged to explode. Thorden anticipated Vess would bring the credits to the tournament, which she did, and the resulting explosion would create a window of opportunity for Aksali Noll, the leader of a bandit group dispatched by Thorden, to seize the map to Okala Five. Noll and her group, known as the Starfallers, were ultimately betrayed by Thorden, who successfully acquired the map.
Vess joined forces with Lando Calrissian, who had also participated in the tournament, to recover the map. Together, they infiltrated Thorden's private bunker located at the Mirogana spaceport, a secret facility unknown to the Empire, effectively deceiving the Governor. Vess concealed herself inside a box that Calrissian presented to Thorden. Calrissian claimed the box contained Tolium gas, a gift for Thorden. Tolium gas was a critical component in the creation of the weapon, as its combination with cyphrite ore resulted in a lethal toxin. While Calrissian diverted Thorden's attention by offering his expertise in mining operations, which Thorden was aware of, Vess successfully retrieved the map. After Vess eliminated the false credentials that Thorden could use against her and created a diversion to allow Calrissian to escape, the two departed with the map, which Calrissian would deliver to the Rebel Alliance. Vess received credits from Calrissian as compensation for assisting the Rebellion in acquiring the map.
Lewis MacLeod provided the voice for Thorden.