- "What becomes of me is of less importance than what becomes of the galaxy."
- ―Gial Gahan
Gial Gahan was a Mon Calamari member of the Galactic Alliance. He had been a Senator for Dac in the Galactic Alliance Senate and by 130 ABY, he was a member of the Triumvirate. Gahan was a staunch supporter of the New Jedi Order, unlike his fellow Triumvir Nu Toreena, who held the Jedi responsible for the Sith–Imperial War. He was later killed by Darth Krayt during an Imperial attack on Dac.
- "I do not deny my actions, but I alone am responsible for them."
- ―Gial Gahan, to Darth Krayt
Following the Alliance surrender at the Battle of Caamas, Gial retired to his homeworld of Mon Calamari, now under Imperial occupation and ruled by the Quarren. There he secretly supplied spare parts, bacta, and other supplies to Admiral Gar Stazi's Galactic Alliance Remnant. He was the uncle of Monia Gahan, a member of Rogue Squadron and one of Stazi's followers.
He was part of the plot to aid Stazi's capture of the Advanced Star Destroyer Imperious. However, he was captured by Imperials under the command of Admiral Dru Valan's forces after disabling the planetary defenses. But this was a diversion so Monia could hack into the station's computer and reprogram the guns to target Imperial ships. Gar Stazi was successful in stealing the Imperious.
Darth Krayt, angered by both the theft of the Imperious and Cade Skywalker's escape from him, arrived on Mon Calamari and proceeded to the Mon Calamari Council. There, he announced to both the council and holonet that one-tenth of the Mon Calamari population would be eliminated. He then had the entire Mon Calamari Council, Calamari and any Quarren who disagreed, slaughtered. Gahan furiously protested this, saying it was genocide, and Krayt agreed and proceeded to execute Gahan personally.