In 3668 BBY during the Great Galactic War between the Galactic Republic and the Sith Empire, members of the Jedi Order and Republic Special Forces Division organized a mission to stop the Dread Masters—a group of six ancient Sith Lords who were terrorizing Republic naval fleets through use of the dark side of the Force. The Dread Masters' power in Sith magic allowed them to remotely and anonymously induce crippling fear in enemy vessels, sending their crews fleeing in panic and seriously damaging the Republic war effort. Despite efforts to keep the six of them hidden aboard a Harrower-class dreadnought, Imperial communications regarding their identity and location was intercepted by the Republic Strategic Information Service, allowing Jedi Knight Jaric Kaedan and a Republic Special Forces team to plan a strike against the Dread Masters. The operation was successful and ended with the capture of the Sith Lords and the Republic's acquisition of a highly-classified . Although their dreadnaught was destroyed, the Masters were kept alive and ferried to The Tomb, a maximum security section of the Republic's secret prison on Belsavis in the Outer Rim Territories.