Ch'gran

Ch'gran was a great Klingon warrior who lived about a thousand years ago. In the wake of the Hurq invasion he urged Klingons to take to the stars. He oversaw the construction of a fleet of seven ships, and on the anniversary of the Hurq invasion, Ch'gran ventured forth into the black sky to conquer the stars for the Klingon people.

The fleet's last word was that they'd found a world on which to plant their flag, and then they were never heard from again. In the 2290s, one ship was found adrift in the Betreka Nebula. In 2328, the wreckage of another was found by the Cardassians on Raknal V. (TLE novel The Art of the Impossible)