The IKS K'tanco was a D7-class, specifically of the K't'inga-class, Klingon battle cruiser starship in Imperial Klingon Defense Force service in the 23rd century, operational in the early 2290s, commanded by Captain Kang, with his wife Mara serving as first officer.
In 2291, the K'tanco saved a Klingon base from an attack by two Romulan warbirds. Shortly thereafter, the K'tanco responded to a distress signal from Klaa's ship, which had been disabled by the Torye's subspace-disruption weapon. Upon arriving, the K'tanco encountered General Navok's ship, and inadvertently discovered two Federation representatives, Spock and Harry Morrow, aboard. Upon learning the Torye's plan to capture a prototype Klingon mobile battle base, the K'tanco set off in pursuit, along with the Federation starship USS Enterprise-A, which had been pursuing the Torye. Together, both ships stopped the Torye and destroyed the base. (TOS - Mere Anarchy eBook: The Blood-Dimmed Tide)
Two years later, in 2293, the K'tanco intercepted the starship USS Excelsior while it attempted to traverse the Azure Nebula on the Federation/Klingon border during an ill-fated attempt to rescue Captain James T. Kirk and Doctor Leonard McCoy from their incarceration on the Klingon penal asteroid Rura Penthe. The K'tanco was damaged in the Excelsior's escape from the confrontation, when Captain Hikaru Sulu ordered an ignition of the sirillium in the nebula. (VOY episode & novelization: Flashback)
- The K'tanco was mentioned as Kang's command in a cut line from the DS9 episode "The Sword of Kahless". In this cut or unfilmed scene, Kor dreamt the K'tanco appeared in the skies above Qo'noS after he brought the Sword of Kahless home and took him to join Kang and Koloth in Sto-Vo-Kor. Also, while not explicitly named in the "Flashback" episode or novelization, it is extremely probable that the battlecruiser encountered by the USS Excelsior was indeed the K'tanco, due to the latter vessel having survived the Torye incident only two years prior. The K'tanco itself was never mentioned to be a D7, but its mirror universe duplicate was, leading to the belief that the two vessels were identical.