Unnamed Romulan warbirds
Unnamed Romulan warbirds:

22nd century

Prototype drone ships 
Two s were modified into a pair of prototype drone ships. ()

24th century

Narendra III warbirds 
These four s attacked and destroyed a Klingon outpost at Narendra III. The  attempted to stop them, but was also destroyed. ()

D'deridex class

Valdore type 

Warbirds