Kathra was a star system.
In 2270, during a conflict between the United Federation of Planets and the Klingon Empire, the Kathra system was occupied by the Klingons, who kept their weapon platform there. Using a captured bird-of-prey with a new type of cloaking device that made it undetectable even to Klingon sensors, Starfleet forces—under direction of Captain James T. Kirk—were successful in gaining scans of the weapon as well as learn their alliance with T'Uerell. The information was presented to Starfleet Command who ordered an immediate offensive against the Klingons to prevent the completion of the weapon's platform. A Starfleet strike force under the command of the USS Enterprise was then assembled which penetrated the Kathra system and destroyed the weapon before it could be used against the Federation. (ST video game: Legacy)