Unnamed D7 class starships
The following is a list of unnamed Klingon and Romulan starships of the .

By commander
 
 Kohlar's battle cruiser
 Kuri's battle cruiser
 
 Tal's flagship

By year

Interceptor near Organia 

In 2267, this warship was sent to Organia by the  Klingon Empire as a prelude to the invasion of that planet. On stardate 3198, the vessel intercepted and attacked the  upon entering the Organian's star system.

After being hit by an unprovoked bombardment of magnetic pulses, the Enterprise returned phaser blasts, completely destroying the Klingon vessel. ()

Klingon invasion fleet 

Following the declaration of , the Klingon fleet was spotted in the quadrant near Organia by Unit XY-75847. 

Soon after, eight Klingon space vehicles, led by Commander Kor, engaged the USS Enterprise, driving it away from the system before they assumed orbit around the planet to deploy their invasion forces. 

The two fleets were later prepared to engage each other outside of Organia, but were stopped by the Organians, who made all instruments of violence on both of the star fleets radiate a temperature of 350 degrees, effectively ending the battle before it began. ()

Confrontation near Capella IV 
 
This warship utilized by the Klingon Empire during the 2260s.

In 2267 this ship transported Kras to Capella IV, so that the Klingon agent could acquire the rare mineral found there called topaline. Kras described the vessel to James T. Kirk as "a small scout ship."

The ship later lured the  away from the Capellan homeworld in an attempt to bolster Kras' position during negotiations, by first relaying false distress calls from the  and . When the Enterprise returned to Capella IV, the warship attempted a brief stand-off, but ultimately yielded. ()

Encounter at Neural 

This vessel carried  to the planet Neural in 2267. 

The vessel was detected by the Enterprise arriving at Neural just as the Enterprise landing party was beaming up to the Enterprise. Because the Enterprise was on the far side of the planet, the Klingon vessel did not spot the Federation ship, which was confirmed when the Klingon's routine message to their home base made no mention of Enterprise. To prevent detection by the ship, the Enterprise maintained radio silence, and after beaming a second landing party down, it left orbit to hide from the Klingon vessel until the Enterprise landing party could complete its mission. ()

Pursuit in the Tellun system 

In 2268 this Klingon battle cruiser, working in conjunction with Kryton, attempted to destroy the  while it traveled through the Tellun system. 

After Kryton sabotaged the warp drive of the Enterprise, it was the job of the battle cruiser to strafe the Federation starship in order to persuade it into engaging its warp drive and destroy the ship. 

The ship was ultimately outmaneuvered by the Enterprise and limped back to Klingon territory. ()

Capture of the Enterprise 

Later in 2268, the Romulan vessel joined Tal's flagship and a Bird-of-Prey in the capture of the USS Enterprise after it crossed into Romulan Neutral Zone. 

They would eventually be outmaneuvered by the Enterprise after it engaged a cloaking device stolen from the Romulan flagship. ()

Encounter en route to Rator III 

In 2269, two Romulan battle cruisers intercepted the  en route to Rator III, as the Federation starship violated the Neutral Zone.

During a brief engagement, the Enterprise disabled the propulsion units of the lead cruiser, and the power supply of the second cruiser, leaving the crew unharmed. Following the engagement the Romulan cruisers to moved off, the latter, according to Spock needed several days to complete repairs. ()

Mousetrap in the Delta Triangle 

Later in 2269, these Klingon battle cruisers, including the , were involved in a mouse trap maneuver against the USS Enterprise in the Delta Triangle. 

The commander of the lead sister ship was Commander Kuri, who contacted the Enterprise after witnessing what he believed to be the destruction of the Klothos, demanding their surrender.

After refusing to surrender, the two sister ships fired on the Enterprise, only to lose it from their sensors after it entered the region of space known as Elysia. ()

Ambush of the Enterprise 

In 2270, three Romulan warships ambushed the Enterprise from behind a type 4 asteroid, just outside the Romulan Neutral Zone. 

They later pursued the Federation vessel deep into Federation space before retreating after failing to capture the ship. ()

Vulcan museum piece  

This battle cruiser was on display at a Vulcan museum on  in 2380. ()

Unnamed Klingon starships
Unnamed Romulan starships
Retconned material in background