A Cerean woman, identified as a member of the female sex, held the esteemed position of Jedi Master. She mentored Lorjan Sakku, who was her Padawan, many millennia prior to the Cold War that occurred between the Sith Empire and the Republic. Her Padawan gave his life to bring his brother, Lyhesh, back from madness. To acknowledge this sacrifice, the Jedi Master honored her deceased student by bestowing upon him the title "Barsen'thor," a term from her Cerean language meaning "Warden of the Order."
Thousands of years before the Cold War between the Galactic Republic and the reconstituted Sith Empire, a female Cerean who possessed a strong connection to the Force was an active member of the Jedi Order. Having achieved the rank of Jedi Master, this Force-sensitive Cerean took on a young Jedi man named Lorjan Sakku as her Padawan, guiding his training. During Lorjan's apprenticeship, his brother Lyhesh, also a Jedi, suffered an attempt on his life and was poisoned. Though Lyhesh survived, the attack drove him to insanity and caused him to embrace the dark side of the Force.
Lorjan, understanding the threat his brother posed to the Order's stability, sought out and confronted the corrupted Jedi. The Cerean's Padawan was successful in redeeming Lyhesh, but this came at the cost of his own life. The Jedi Master, recognizing the selfless act of her former Padawan, honored Lorjan posthumously with the title "Barsen'thor," which translates to "Warden of the Order" in Cerean language. The Jedi Order later adopted this title as an official ceremonial rank, awarding it only to those individuals who demonstrated exceptional wisdom and skill in service to the Order. Some time after Lorjan's passing, the Jedi Order proclaimed a second Barsen'thor, and a third individual was later deemed worthy of the title during the Cold War, millennia after the first.
The 2011 massively multiplayer online role-playing game Star Wars: The Old Republic, developed by BioWare, first introduced the title of Barsen'thor. The 2012 publication Star Wars: The Old Republic Encyclopedia mentioned the Cerean Jedi Master, providing background information on the Barsen'thor title.