A Jedi individual lived thousands of years before the Cold War between the Galactic Republic and the reconstituted Sith Empire. The Jedi, who showed exceptional skill and wisdom, was the second person in the history of the Jedi Order to be granted the prestigious title of "Barsen'thor," a Cerean word for "Warden of the Order."
The Barsen'thor served the Jedi Order.
Millennia before the conflict known as the Cold War—which was fought between the Galactic Republic and the reconstituted Sith Empire—a Force-sensitive individual was found by the Jedi Order and trained as a Jedi. At some point in the Jedi's career, the individual was recognized by the Jedi Order for exceptional accomplishments by being granted the honorific title of "Barsen'thor," which translated to "Warden of the Order" from the Cerean language.
Up until that point, the title had been used only once in the entire history of the Order, when it was posthumously bestowed upon the Jedi Padawan Lorjan Sakku, in memory of him sacrificing his life to protect his fellow Jedi from his insane brother Lyhesh.
By awarding that title to the second Barsen'thor, the Jedi Order acknowledged the individual as possessing great wisdom and skill, comparable to Sakku's. After the second Barsen'thor's tenure, it would be thousands of years until that ceremonial rank would be used again, when it was granted during the Cold War to a Jedi Consular who prevented the near-eradication of the Jedi Order by the Sith-engineered disease called the Dark Plague.
The second Barsen'thor was indirectly mentioned in the 2011 massively multiplayer online role-playing game Star Wars: The Old Republic, developed by BioWare. During the course of the story, one of the game's playable character classes, the Jedi Consular, attains the title of Barsen'thor, and it is stated that he is the third person in the history of the Jedi Order to have been granted that title, and it has been thousands of years since the last recipient—the second Barsen'thor.