Kel'eth Ur was once a Sith Lord from the reconstituted Sith Empire, a male Human who made his home on Dromund Kaas. Near his life's conclusion, he came to believe that only temporary power came from passion and that genuine power existed in serenity - a belief typically held by the Jedi. Alaric recounts that the Emperor executed him in 4606 BBY for his heretical views.
His accumulated wisdom was preserved within a holocron, discovered in the Dark Temple during the era of the Cold War.