Knights of The Old Republic
The book Secretum Secretorum which in old basic translation means The Secret of Secrets.
During the hyperspace war 1,000 years ago Tapani was drawn into the conflict and worked with Jedi to battle Sith in the Tapani Sector. A darklord of the Sith plagued the systems for nearly a year. Death and Terror became the people’s daily fare. The Jedi provided assistance where they could, but the Hyperspace War was vast and what the Tapani were told they were mostly on their own, awaiting more Jedi help.
The Sith Lord was elusive and manipulative. The Lords of nine houses banded together to stop this threat. The Hi-Lords took terrible and shameful measures to stop the Sith Lord. Each house recorded elements of their sacrifices and wicked acts they had made to stop this evil Sith Lord. Not wanting to have made public the houses agreed to keep these accounts secret. All houses would suffer shame and thus was mutually assured destruction.
These books had been passed down for over a hundred generations along with other items to Privy Councilors for safe keeping.