Captain K'Temoc was the commanding officer of the Klingon K't'inga-class cruiser, IKS T'Ong. In 2290, the T'Ong was dispatched on a crucial mission for the Klingon High Command at the time the Federation and Klingon Empire were at war.
In 2365, the T'Ong returned from that mission, unaware of the changes in relations between the two powers. Special Emissary K'Ehleyr was dispatched to the USS Enterprise-D on a priority mission to intercept the T'Ong before its crew woke up and attacked any Federation colonies. (TNG: "The Emissary")