Tiber Saxon, a male Mandalorian, took on the role of governor of Mandalore after the death of his brother, Viceroy Gar Saxon. During the Mandalorian Civil War against Clan Wren and House Kryze, Saxon utilized "the Duchess," a weapon mounted on a customized AT-DP. This weapon, originally conceived by the Mandalorian Sabine Wren, was engineered to target and vaporize individuals wearing Mandalorian armor. Saxon's life ended when Wren and her allies infiltrated Saxon's Star Destroyer, stationed at Sundari, with the goal of destroying the weapon. They succeeded, leading to the destruction of Saxon's vessel with Saxon still aboard.
Following Gar Saxon's death at the hands of Clan Wren, Tiber Saxon inherited the position of governor of Mandalore from his brother, serving the Galactic Empire. Seeking dominance over the rebellious clan and their allies in the civil war, Tiber oversaw the reconstruction of the Arc Pulse Generator, a superweapon also known as the Duchess, which Sabine Wren had created during her days as a cadet at the Imperial Academy of Mandalore. This weapon was designed to eliminate Mandalorian warriors by targeting the beskar alloy in their armor, causing it to superheat and disintegrate the wearer. Sabine had erased the plans and sabotaged the prototype before defecting, horrified by the Empire's intention to use her creation against her own people. Tiber, who favored Imperial Jumptrooper armor made of plastoid over Mandalorian armor, was unconcerned by these implications.
Later, Tiber discovered that Sabine had returned to Mandalore to rally support for the growing rebellion and to locate her father, Alrich Wren, who was being held hostage by the Empire to ensure his family's cooperation. Tiber moved Alrich from the capital of Sundari to a remote prison to isolate him from his contacts. Upon learning of Sabine's planned attack on the prison, Tiber secretly arranged for Alrich to be transported back to Sundari via convoy, intending to ambush the rebels.
However, Sabine's attack succeeded, aided by reinforcements led by Bo-Katan Kryze. Sabine's mother, Countess Ursa Wren, had discovered Alrich's true location but was unable to warn her daughter sooner due to Imperial jamming. The Imperial convoy transporting Alrich was ambushed by the rebels, and Tiber ordered his men to remain in position, expecting reinforcements. The Imperial Troop Transport carrying Alrich and its two escorts diverted into a canyon, where they were attacked by Sabine, Kryze, Fenn Rau, Ezra Bridger, Kanan Jarrus, and Chopper, who successfully rescued Alrich. Tiber then deployed "the Duchess" against the Clan Wren warriors at the original battle site, resulting in numerous casualties. Ursa and Tristan Wren narrowly avoided the weapon's effects due to a warning from Sabine, who recognized its sound over the comms.
Aboard his own Star Destroyer, Tiber presented the results of the Duchess's test to Grand Admiral Thrawn. The Grand Admiral acknowledged its power but noted that Tiber was concealing its limitations, specifically its short range. Thrawn suggested capturing Sabine to improve the weapon, a proposal Tiber accepted. Captain Hark continued to voice his concerns about the Duchess, fearing that the Empire would eventually turn it against all Mandalorians. Tiber, aware that the rebels could not ignore such a threat, set a trap.
His trap was successful, as a rebel team led by Sabine arrived to destroy the Duchess. Tiber confronted Sabine and Kryze, demanding that Sabine recalibrate the weapon to consolidate his control over Mandalore. Hark protested, suspecting that the Empire would betray them, prompting Tiber to use the weapon on him. After Tiber threatened to kill Kryze, Sabine agreed to recalibrate the Duchess, leading him to temporarily deactivate it. However, Sabine secretly reprogrammed the Duchess to target Imperial armor instead. When Tiber attempted to electrocute the three Mandalorians, he was shocked to find himself targeted by the Duchess. The weapon's reactivation was powerful enough to incapacitate all of the Imperial soldiers on the Star Destroyer. Sabine considered killing Saxon with the weapon, but Kryze dissuaded her, arguing that it was a dishonorable tactic. Hark seized the opportunity to escape. Sabine then used the Darksaber to breach the weapon's core, and the strike team fled before the Star Destroyer exploded, killing Tiber.
Like his brother Gar, Tiber Saxon pledged allegiance to the Empire in exchange for power. Tiber Saxon was extremely ruthless and desired the Emperor's respect. However, unlike Gar, Tiber was prepared to abandon all aspects of his Mandalorian heritage, claiming that the culture needed to "evolve" with the times. To demonstrate this, he wore Jumptrooper armor made of plastoid instead of the Imperial Super Commando armor worn by his brother, which was made of beskar. He sought absolute submission from his people and was willing to use the Duchess to kill countless individuals to achieve it. Tiber's embrace of Imperial ways stemmed, in part, from his belief that Emperor Palpatine had shown him the path to true power. He was ruthless and would attempt to defeat anyone in his way, including Captain Hark, one of his own men.
Tiber Saxon was voiced by Tobias Menzies in Star Wars Rebels: Heroes of Mandalore.