The Battle of Chyron Belt was a conflict. It occurred around the time of the First Order-Resistance War in 34 ABY. The battle's name comes from the Expansion Region planetoid called Chyron. Amilyn Holdo took part. She had previously served with the Rebel Alliance during the Galactic Civil War. She later rose to the rank of Vice Admiral in the Resistance.
By the year 34 ABY, Commander Poe Dameron of the Resistance had become aware of Holdo's involvement in the Battle of Chyron Belt. This was despite never having met the Vice Admiral face-to-face. In that year, Dameron was present at a briefing on the Resistance cruiser named Raddus. Holdo, after being given command of the Resistance fleet, gave a speech to the assembled Resistance members. Following her address, Dameron inquired of his fellow pilot, C'ai Threnalli, whether the unconventional Vice Admiral was indeed the same individual who had fought in the Battle of Chyron Belt. Threnalli simply shrugged and gave an affirmative reply in the Abednedish language.
The 2017 film Star Wars: Episode VIII The Last Jedi from the sequel trilogy was the first place the Battle of Chyron Belt was mentioned. In the second issue of the comic adaptation of the film by Marvel Comics, written by Gary Whitta and released on May 23, 2018, Poe Dameron says a different version of the line referencing the battle to Amilyn Holdo. In this version, the battle's name is incorrectly spelled as "Battle of Chryon Belt." The non-canon adaptation William Shakespeare's Jedi the Last: Star Wars Part the Eighth by Ian Doescher, which was released on July 10, 2018, introduced "Clash of Chyron Belt" as an alternative name for the battle. In this adaptation, yet another version of the line is delivered as an aside.