D7 class

The D7 class battle cruiser was a type of warship designed and built by the Klingon Empire during the mid 23rd century. Following the formation of a Klingon-Romulan alliance in the 2260s, many D7s entered service in the Romulan Star Empire as Stormbird-class cruisers. (TOS episode: "The Enterprise Incident," FASA RPG: ''The Romulans: Star Fleet Intelligence Manual).

A variant of this cruiser was the D7-A, which saw use as early as 2269. (FASA RPG: Star Trek IV Sourcebook Update).