I saw references in some newer Disney canon to Admiral Ackbar's first name being Gial.
What was the history of the name Gial (as in, how and when did it appear in canon)?
More importantly, what was his first name - if any was stated - in prior canon, including various EU/Legends levels?
His name is Gial Ackbar in both Expanded Universe and new Disney Canon.
Gial is simply a name he was referred to in The Essential Guide to Warfare in 2012 and his Expanded Universe canon, and transferred to Disney Canon in Star Wars: Absolutely Everything You Need to Know in 2015.
The first reference to his forename seems to have been in The Essential Guide to Warfare
Gial Ackbar was born into a prominent merchant clan in the city of Foamwander, served his planet's king during the Clone Wars, and held high military and political office m the early years of the Imperial era. At first. Ackbar saw the New Order as restoring Republic law and justice—but the Empire soon brought an invasion fleet to his homeworld. The peaceful cultural and technological achievements of Dac had to be suppressed to preserve the idea of human superiority.
This name was then canonised in the index of Star Wars: Absolutely Everything You Need to Know.
Admiral Gial Ackbar - P171
Interestingly, in the excellent Making of Star Wars: Return of the Jedi we learn that Lucas and the crew would refer to the Ackbar puppet on the dailies as Ernie Ackbar.
Main unit next moved to Stage 5 and the rebel briefing room, which meant first days for Blakiston, Crowley, and Tim Rose (Ackbar, or, sometimes, “Ernie” Ackbar, on the Progress Reports). In wide shots, Ackbar was a man in a suit; in closeup, a puppeteer would manipulate his facial movements from below. Although still “immersed” in Poltergeist, Richard Edlund arrived to oversee the VistaVision shots on that set because, in postproduction, a hologram of the Death Star was to be added by the Computer Division.
