Tenebrae's mother was a female Sith farmer who was the mother of Tenebrae who later became the Sith Emperor, and the wife of Tenebrae's father.
In 5107 BBY her son Tenebrae discovered that he was Force-sensitive. Her husband confronted her about Tenebrae's power, to which she admitted that she had an affair with the ruling Sith Lord. Her husband attacked her in a rage, and she was saved by her son, who snapped his "father's" neck with a mere thought. As punishment for being unfaithful and betraying her family, Tenebrae tortured her for months using the Force until he eventually killed her, while he honed his Force powers.
Dramath mentioned her again when he told Tenebrae that she should have killed her son under his orders by drowning him. Tenebrae claimed to have ended his mother's suffering long ago.
Tenebrae's mother was first mentioned in Drew Karpyshyn's novel The Old Republic: Revan, which was released on November 15, 2011.
- Star Wars: The Old Republic Encyclopedia