Klingon battle cruiser class of the 22nd century and the Empire's principal capital ship in the era of Enterprise NX-01.
The D5-class was the main Klingon capital ship of the mid-22nd century. Its layout set the pattern that later Klingon cruisers would follow, with a small forward hull on a long boom connected to a larger engineering section, aft impulse engines and two warp nacelles on swept-back pylons.
D5 cruisers appeared repeatedly during Jonathan Archer's encounters with the Klingon Empire. The type served for decades, and in Once More Unto the Breach the aging warrior Kor recalled that his old command, the Klothos, had been a D5.