The Core Founders are represented by the Unity Arc
Around 25,000 BBY, the Galactic Republic was established by a collective of twenty-two worlds known as the Core Founders. These worlds were all situated within the Core Worlds region. Alderaan, Chandrila, Corellia, Coruscant, and Duro were among these founding planets. In honor of this group, the Avenue of the Core Founders was constructed in front of the Galactic Senate Building on Coruscant, the capital of the Republic, adorned with statues symbolizing each of the worlds.
Created for the Valo Republic Fair in 231 BBY, the Unity Arc served as an artistic tribute to the Core Founders. It featured twenty-two orbs suspended in the air, with each sphere representing a different Core Founder. Harli Cogra, a Jedi Master, referenced both the Unity Arc and the Core Founders within Chronicles of the Jedi, a record documenting the Jedi during the High Republic era, penned in 229 BBY.
The Core Founders received their initial implicit mention within the present Star Wars canon through the reference book Star Wars: Complete Locations, released on September 27, 2016. Subsequently, they were explicitly identified in Star Wars Propaganda: A History of Persuasive Art in the Galaxy, a reference book authored by Pablo Hidalgo and published on October 25 of the same year. Within the Star Wars Legends continuity, the Core Founders were initially referenced in the 2000 reference book Inside the Worlds of Star Wars: Episode I, which was written by Kristin Lund.