The K'tralli were a Vulcanoid alien species who lived on their homeworld of N'trahn in the K'tralli system situated close to the Romulan Neutral Zone.
They were actually descended from the same racial stock as the Vulcans and the Romulan species. However, they were considered a distant offshoot civilization that formed their own culture with no traits similar to their racial forebears beyond their physical appearance. Unlike the Vulcans, the K'tralli expressed their emotions yet lacked the aggressive qualities seen within the Romulans. In addition to sharing a physical appearance, a K'trall's readings were incapable of being distinguished to a Romulans according to sensor scans. Furthermore, their physical form resembled a mixture between that of a Vulcan and a Romulan. As such, K'tralli could pass for Romulans and even Romulans could disguise themselves as a K'trall. In time, they formed a monarchy styled government that dominated much of their history. From their homeworld of N'trahn, the K'tralli moved out to settle four other inhabited planets within the sector. These included the planets A'tray, L'ahdor, D'rahl and S'trayn. Ten years prior, a revolution led by General H'druhn occurred that led to the fall of the monarchical rule and brought about the establishment of a dictatorship with the military leader becoming the Overlord of the K'tralli Empire.
- The mention of the species being a distant offshoot and from the same racial stock as the Vulcans indicates that they may have been part of the Diaspora that erupted from the Sundering of Vulcan.
First contact with the United Federation of Planets came approximately in 2330. This was during a point when the K'trall's economy was in a state of near complete collapse and their provisional government was having many difficulties in bringing about the promise of democratic reforms. This became one of the reasons why they welcomed Federation support as they required economic aid and the benefits of opening trade. As a result, a treaty was negotiated that saw the K'tralli became members of the Federation and saw the granting of colonization rights over the planet that became known as Artemis VI. Starbase 37 was later established around 2335 where it was stationed in orbit around Artemis VI which was the only Federation colony in the K'tralli system. The Starbase was intended to serve as a diplomatic outpost with the K'trall as well as serve the administrative needs for the colony it orbited with this duty encompassing the next thirty five years. By the mid-24th century, the Federation ambassador to K'trall had died of natural causes and there was no official representative to the K'tralli. A new ambassador was later designated and Captain Ivan Gruzinov was selected for this role. By this point, General H'druhn passed the reigns of power to his son J'drahn who Captain Gruzinov found more difficult to deal with compared to his father.
By this point, there were rumors of secret negotiations between the K'trall and the Romulan Star Empire. In addition, it was suspected that Overlord J'drahn or some of his military governors had been providing support to pirates to prey on merchant shipping lanes in the sector. Chief amongst them being Captain Diego DeBlazio who took the name of Captain Blaze whose father was a Federation diplomat named Dominic DeBlazio and mother M'tala, a native K'tralli from a prominent family. One of the dangers posed by Captain Blaze was his acquisition of Constitution-class starship called Glory and had outfitted it with a cloaking device that possibly indicated ties to the Romulans. In 2370, the USS Enterprise-D received orders from Starfleet Headquarters to travel to Starbase 37 in orbit above Artemis VI. Commander William T. Riker had not read anything on the K'tralli system since his time at Starfleet Academy and intended to read up on them prior to the mission but lacked the time to refresh his memory. As such, he attended the briefing where Lieutenant Commander Data accessed his memory files in order to provide a summary on the star system as well as the K'tralli species.
Captain Gruzinov managed the briefing where he highlighted the dangers of Romulan involvement. Furthermore, he indicated that any support between J'drahn's government and the Romulan Star Empire would lead to the K'trall's expulsion from the Federation. This in turn would lead to a collapse in the economy of the K'tralli Empire due to the lack of Federation trade and support. A resultant action would lead to the ruling dictatorship seeking support from the Romulans in order to avoid another revolution which in turn would see J'drahn becoming a puppet leader to the Star Empire that would gain holdings on the Federation side of the Neutral Zone. (TNG novel: Blaze of Glory)