Operations Group One, which was also referred to as Special Operations Group One, represented one of the five Special Operations teams dispatched by the re-established Sith Empire to the Belsavis correctional facility amidst the Belsavis Invasion throughout the Galactic Conflict, with the intention of discovering and liberating the Dreadful Masters. Under the command of Andreaus Thos, a Sith Lord, Operations Group One managed to penetrate the area of the correctional facility recognized as the Tomb, assisted by Special Operations Group Two. Group Two then set up a forward operating base while Group One proceeded further into the Tomb; however, the Imperials inadvertently released the brutal Esh-kha race from their suspended animation, resulting in significant casualties. A segment of Group One located the Dread Masters within Vault 914 but met their demise at the hands of the Esh-kha, while Thos guided another portion of the group toward stasis block 44 to release additional Sith detainees, although his troops sustained substantial losses inflicted by the Republic forces.