Yaga Auchs was a Mandalorian fighter of Human descent who participated in the conflict known as the Sith–Imperial War. Instead of showing allegiance to the legitimate Mandalore, Chernan Ordo, he instead pledged his fealty to a separate entity with the goal of removing the Mandalorians from the ongoing war.
Following his act of treachery against Hondo Karr and Ordo during the Battle of Botajef, Auchs assumed leadership over the surviving Mandalorian troops. Consequently, he declared himself to be the new Mandalore and successfully kept the Mandalorian warriors from engaging in any further combat during the war.
During the Second Imperial Civil War era, Auchs still maintained his position of power over the Mandalorians. Unbeknownst to him, Hondo Karr had survived his betrayal. After reuniting with his former spouse, Karr made his way back to the Mandalorians, seeking to hold Auchs accountable for his actions and to get retribution on the disloyal Mandalore.