Galaxy X class

The Galaxy X-class was a type of Federation starship, a dreadnought-type subclass of the design, in Starfleet service at the end of the 24th century, and were expected to continue in service into the 25th century. 

History and specifications
The Galaxy class was refitted at the turn of the 25th century, after the collapse of the Khitomer Accords in 2399. In response to increased hostility with the Klingons, the newly redesigned ship was equipped with an spinal lance weapon and a cloaking device since Starfleet was authorized to develop and implement cloaking technology on selected ships.

The additional engine nacelle assembly greatly increased the ship's speed and power. 

By the year 2409, Galaxy X-class starships, like USS Victory (NCC-170147), were equipped with cloaking devices and served as flagships of fleets. 

Some of these vessels were equipped with phaser spinal lances.

In the same year, vessels of the class were used by the Terran Empire's Imperial Starfleet. One such vessel was the, which led a Terran invasion of the prime universe. 

In a possible future timeline, the USS Enterprise (NCC-1701-D) had been converted to the specifications of this class by the 2390s, although that reality was aborted when Q made Jean-Luc Picard aware of how his fate would unfold.