Dreadnought class (Klingon Empire)

The Dreadnought class starship was a class of ship developed secretly by the Klingon Empire in the 2270s to be used as a first-strike weapon. It contained a cannon capable of destroying a planet.

History
In 2273, a vessel of the Dreadnought class was located by the refit USS Enterprise (NCC-1701) along the path taken by V'Ger. An intact section was boarded by James T. Kirk, Spock, and Romulan subcommander T'Cel of the ChR.

The dreadnought had been destroyed by "Critters", a race which had previously attacked the USS Farragut (NCC-1702) in 2257 and captured a D7/ in 2267. Remains of Critters were scattered throughout the wreck. Kirk and T'Cel discovered its planet-destroying cannon and mutually agreed to avoid interstellar war by not reporting the find to their governments. To ensure a balance of power with the Klingons, however, Kirk informed the Klingon government that he’d kept a copy of the cannon’s schematics.

The loss of the ship by QuchHa'  Klingons and the resulting exposure of its existence had significant ramifications within the Klingon Empire. The HemQuch Klingons used the incident to have the QuchHa'  Klingons discommoded, banished and relegated to backwater duties.