This ship was the mainstay of the Imperial Fleet until the D7 Battlecruiser was designed. Unable to be upgraded to the improved design, the D6 was used for a series of fleet support variants, assigned to backwaters or sold to the Romulans (before the alliance ended in betrayal). Its largely short range firepower led to the ship being used as an escort towards the end of its operational life, unable even to compete with the original incarnation of the Constitution class ships.

Some of these ships still exist, in service with minor noble houses or rotting on picket duty in backwaters. A number of these hulls were converted to survey cruisers and sent outside the empires boundaries to explore. Some of these ships have yet to return. Some D6 hulls have even become civilian transports.