Commander Kruge was the commanding officer of Klingon forces of the Axis of Empires. In that capacity, he recruited his lover Valkris to obtain intelligence on the Genesis Device, a Federation technology designed to instantly terraform an entire planet. He was killed during the Axis Civil War.
Kruge entered the Klingon Defense Force as a member of a political house with family ties to the Klingon Emperor; specifically, Kruge was a favored cousin of Emperor Kahless IV.
As of 1964 N.E, Kruge served as gunner aboard the IKS Kut'luch, a D6-class battle cruiser, under the command of Commander Kor. In October 1964 N.E, Kruge was serving as gunner on the bridge when Kor launched an attack against the Allied Task Force to prevent their entering the Tarsus system. Although Kruge was able to inflict damage on four ships, Allied starship was able to launch a stronger attack against the Kut'luch and disabled the vessel. When Kor ordered the Kut'luch to withdraw, Kruge began to question his captain's orders, but later stood down. However, Kor believed that Kruge would one day challenge him.