Bail Antilles, a Human male, was a politician who advanced through the Galactic Alliance's bureaucracy. Before 130 ABY, he became one of the three members of the governing Triumvirate. He was known for his calm demeanor and careful decision-making, often casting the deciding vote between his fellow Triumvirs, Gial Gahan and Nu Toreena. Stationed on the Alliance capital world of Coruscant, Antilles had a daughter named Ona.
During the Alliance's Sith–Imperial War against the Galactic Empire, Antilles served in the Triumvirate. This period saw many Alliance member worlds defect to the enemy. When Rear Admiral Piers Petan suggested attacking a lightly defended Emperor Roan Fel on the planet Caamas, Antilles's vote proved crucial. Despite suspicions of a trap from Jedi Master Kol Skywalker and Admiral Gar Stazi, Antilles believed the struggling Alliance needed to take the chance. The Empire's trap was sprung at the Battle of Caamas, leading to the Alliance's surrender and the end of the war. The Triumvirs were replaced with Imperial loyalists, and Antilles died sometime before 137 ABY.

Bail Antilles, a Human male, hailed from a family committed to government service. Before the year 130 ABY, he became a politician within the Galactic Federation of Free Alliances, a federation of member worlds and associated autonomous states operating under a constitution. At some point, he fathered a daughter, Ona Antilles. Antilles's natural charm, connections, and respected family name allowed him to climb the political ladder, eventually securing a position in the Galactic Alliance's governing Triumvirate. Based on the Alliance's capital world of Coruscant, Antilles served alongside the Mon Calamari Gial Gahan and the Ithorian Nu Toreena, all three having been elected by the Galactic Alliance Senate. Each Triumvir worked independently with specific government offices and advisory councils. They also frequently consulted with members of the New Jedi Order, who were allied with the Alliance. Decisions and policies required a majority vote from the Triumvirate, and Antilles's level-headedness often made his vote the deciding factor.
The Triumvirate encountered a major crisis in 127 ABY. The Jedi had been collaborating with the Yuuzhan Vong—a species widely hated and feared in the galactic community due to their war of conquest a century earlier—to use Yuuzhan Vong terraforming technology to restore devastated worlds in an initiative known as the Ossus Project. However, the One Sith secretly sabotaged the project, causing deadly mutations in the populations of the terraformed worlds. The galaxy erupted in outrage, but the Jedi persuaded the Galactic Alliance to support the Yuuzhan Vong. When the Galactic Empire demanded retribution and declared war on the Alliance, Antilles, Gahan, and Toreena found themselves leading their government through the Sith–Imperial War.
As the Empire capitalized on the Ossus Project's failure to attract new worlds to its side, the Alliance steadily lost systems and crucial military resources. Many of the war strategies devised by Antilles and the Triumvirate proved unsuccessful, but the Empire faced resistance from the Force abilities of the Jedi. However, one year into the conflict, the Sith emerged from hiding and joined the Empire's forces. Over the next two years, the Empire achieved numerous victories. By 130 ABY, factions within the Alliance, feeling the organization was suffering greatly, sought a swift end to the war. When Rear Admiral Piers Petan received information that Emperor Roan Fel and a small escort would be secretly meeting with representatives from the Hapes Consortium and Chiss Ascendancy in orbit near the planet Caamas, he presented a plan to the Triumvirate on Coruscant: send all available ships to Caamas, capture or eliminate Fel, and force the Empire to negotiate peace.

Also present at the meeting were Jedi Master Kol Skywalker and Admiral Gar Stazi, both of whom suspected the intelligence was a deliberate attempt to draw the Galactic Alliance Core Fleet away from Coruscant and into an ambush. Gahan sided with the Jedi and voted against the action, while Toreena supported Petan, leaving the final decision to Antilles. Despite his reservations, he reluctantly agreed, believing they needed to take the risk. The Battle of Caamas proved to be a trap, and the Alliance fleet was defeated while the Sith simultaneously attacked the Jedi on a defenseless Coruscant. Petan surrendered to Imperial Grand Admiral Morlish Veed, effectively ending the war. The Empire seized control of every Alliance member world, and the Galactic Alliance was dissolved.
The Empire maintained the Alliance bureaucracy, adapting the existing political and governmental services to suit its new regime. While the Triumvirate was kept in place, Antilles and his colleagues were quickly replaced by Imperial loyalists. The Triumvirate became an executive body under the command of the Emperor, who was soon usurped by the Sith Lord Darth Krayt and forced into exile. Lord Krayt's Empire faced a challenge from Admiral Stazi, who had escaped Caamas and formed the Galactic Alliance Remnant. Ona Antilles served Stazi as a lieutenant. Bail Antilles passed away sometime before 137 ABY, by which time Ona no longer gave him much thought.
Bail Antilles's family name, connections, and personal magnetism facilitated his rise through the Galactic Alliance's political ranks. As a member of the Triumvirate, he was known for carefully weighing all options and avoiding unwavering adherence to any particular organization or policy. Antilles was viewed as level-headed, often casting the deciding vote between the Jedi-sympathetic Gial Gahan and the quick–fix–oriented Nu Toreena. When considering whether to attack the Empire at Caamas, Antilles considered the opposing arguments of both Piers Petan and Gar Stazi before ultimately deciding to risk the attack—Antilles believed the Alliance, lacking support from numerous systems, was slowly bleeding to death.
Antilles had brown hair, blue eyes, and light-colored skin. He was fluent in Galactic Basic Standard, Durese, High Galactic, Mon Calamarian, and Sullustese. He possessed fine clothing, a blaster pistol, an encrypted comlink, and a datapad.
Bail Antilles was introduced to the Star Wars Expanded Universe by John Ostrander and Jan Duursema, the creators of the Star Wars: Legacy comic series. He first appeared in a flashback in the series' twentieth issue, with pencils by Omar Francia, released in February 2008. Additional information about the character was provided in the Legacy Era Campaign Guide (2009), authored by Rodney Thompson, Sterling Hershey, and Gary Astleford.
The name "Bail Antilles" has a substantial history in both Star Wars Canon and Legends. It first appeared in George Lucas's 132-page early draft of the original Star Wars film, completed in May 1974. That character was eventually renamed Bail Organa, and a different Bail Antilles was later referenced in the 1999 film Star Wars: Episode I The Phantom Menace. Furthermore, Murder on the Executor, a 2009 Wizards of the Coast roleplaying adventure, used "Bail Antilles" as an alias for a Rebel Alliance operative. Stephen J. Sansweet of Lucasfilm has stated that "Antilles" is a very common name in the Star Wars universe, similar to common surnames like "Jones" or "Smith" in some English-speaking countries.