A moon where Federation and Klingon forces fought during the war, and where M'Benga and Chapel served in a field hospital.
J'Gal is a moon fought over during the Federation-Klingon War, at the center of Under the Cloak of War. Joseph M'Benga and Christine Chapel served at a Starfleet field hospital there and witnessed the brutality of the Klingon forces under General Dak'Rah.
Dak'Rah later defects and claims to have killed his own officers on J'Gal for ordering attacks on civilians. M'Benga reveals that Dak'Rah gave those orders and that he himself killed the officers, and the confrontation ends with M'Benga killing Dak'Rah.