The massive D'deridex-class, or Type-B, Warbird was one of the most advanced vessels in the Romulan Star Empire and served as the backbone of the Romulan fleet during the mid-to-late-24th century.
Roughly twice as long as a Federation Galaxy-class starship, the D'Deridex-class Warbird had a notable advantage in fire power, over its Federation counterpart, but a lower overall maximum speed and less combat maneuverability.
Like earlier Romulan warships, D'deridex-class Warbirds were equipped with cloaking devices, which protect them from detection in most evasive situations. However, cloaked Warbirds radiated a slight subspace variance at warp speeds; therefore ships traveling at speeds above warp 6 run a much greater risk of being detected through their cloak. While traveling under cloak, all electromagnetic emissions, including communications, aboard a Warbird were carefully monitored.
The emergence of a D'deridex-class Warbird in 2364, during an encounter with the USS Enterprise-D on the edge of the Neutral Zone, signaled the end of a fifty-three year Romulan isolation.