Evereni was the tongue spoken by the sentient beings of the same designation, who originated on their birthplace, the world of Everon. The Evereni people gave their family groups names based on actions, and their own appellation—"Evereni"—translated to "those who take care." Following the abandonment of their planet in 500 BBY, the Evereni maintained the use of their language for many generations. The Evereni privateer commander Marda Ro came across the language during her meeting with a fellow Evereni who identified himself as "Isren," who instructed her in some Evereni expressions. Ro found the language to have a fluid quality and later recorded her thoughts on it within diary entries intended for her progeny.
By 252 BBY, her female descendant Shalla Ro imparted to her own grandson Marchion Ro—who, by that year, had been exposed to his great-great-grandmother's recordings referencing Evereni—the significance of items linked to the Ro name. He recalled this lesson years afterward while examining his family's archives.
Evereni was the lingo utilized by the original inhabitants of the tempestuous world of Everon, the near-human Evereni. The Evereni embraced the natural world of their native land and cared for Everon, referring to themselves as "caretakers" in their own vocabulary. Evereni families received names derived from actions, which were passed down as directives.
Marda Ro—the Evereni who established a marauding organization that would eventually evolve into the Nihil—felt that the language possessed a slippery quality upon her initial exposure to it.
This manner of speech originated on Everon and was in use by the era its residents, the remaining Evereni, left behind the planet in 500 BBY. Its usage persisted among surviving Evereni during the generations following their departure from Everon.
Sometime after 379 BBY, Marda Ro located "Isren," an Evereni who, instead of his given name, used the Evereni term meaning "old uncle" to identify himself. Isren was present on the galactic frontier planet Ryloth, in pursuit of the creatures known as lyleks within Ryloth's jungles. Having been raised outside of Evereni culture, Ro sought greater understanding of her people, and Isren shared information about the Evereni, introducing her to their language and teaching her certain expressions in Evereni. However, he declined to reveal the meaning of her surname to Ro.
Ro eventually encountered other Evereni, the siblings Vika and Velya Faer. They provided Ro with further insights into the Evereni and their language, including naming conventions and the significance of her surname. Ro documented both encounters and several of the terms she had learned in communications intended for her descendants, whom she fondly referred to as her "Riferi," the Evereni word for "legacy."
By 252 BBY, Ro's granddaughter Shalla Ro had instructed her grandson Marchion Ro on the utility of anything connected to the Ro name, including Marda's journal. By that year, Marchion had listened to the memoirs, including the entries where Evereni was mentioned. In 230 BBY, Marchion—who had by then become the current leader of the Nihil—was acquainted with the language and knew at least one of its words, and two rotations later, he remembered the lesson imparted by his grandmother while examining his family's records.
Evereni received an indirect reference in the initial edition of the 2022 illustrated story miniseries Star Wars: The High Republic: Eye of the Storm. Charles Soule authored the issue, which Marvel Comics published on January 12, 2022, as part of Phase I of the Star Wars: The High Republic multimedia project. Before the comic's release, the language was initially alluded to in a sneak peek of the issue that was made available on StarWars.com on January 5 of the same year.
The language later appeared in and was identified by name in the short story "A Closed Fist Has No Claws," penned by Tessa Gratton and featured in the 2023 young-adult anthology The High Republic: Tales of Light and Life. In an interview, Gratton revealed that they are frustrated by the absence of naming conventions in Star Wars, which motivated her decision to create one for the Evereni. The naming convention was one of the first parts of the story he created. Gratton also mentioned that expansions on Evereni lore introduced in Eye of the Storm—such as the language, which "A Closed Fist Has No Claws" provided more details for—were her second favorite part of writing the short story.