During the mid-23rd century, a Klingon sect came into control of the cruiser, a sect which believed that the Empire had lost its way and become corrupt. After having discovered a set of sacred scrolls that laid out a journey to a distant region of the galaxy to seek the kuvah'magh, the crew decided to launch during the latter half of the 23rd century. They boarded the D7-class cruiser and left Klingon space. For the next century, the ship traveled thirty thousand light years into the Delta Quadrant, and therefore the ship became a generational ship.
In 2377, the battle cruiser encountered the Federation starship USS Voyager. Believing that the Empire was still at war with the Federation, Kohlar ordered an approach while cloaked, and then decloaked suddenly, fired on Voyager, and quickly recloaked. During the initial attack, the battle cruiser inflicted moderate damage to Voyager's port shields, causing them to drop fifty percent. Despite the initial tactical advantage, Voyager was able to detect the battle cruiser by performing a metaphasic scan, and promptly disabled the cruiser's cloaking device and forward disruptor emitters with their phasers.
Kohlar, who was attempting to buy time for repairs, replied to Voyager's hail. Voyager's Captain Kathryn Janeway revealed to Kohlar that there was a treaty in effect between the two powers, and she asked that the Klingons stand down. Unconvinced of Janeway's statement, Kohlar agreed to transport aboard Voyager to meet the ship's chief engineer, the pregnant half-Klingon B'Elanna Torres.
Upon returning to his ship Kohlar convinced his crew that he had found what they were seeking in the Delta Quadrant, the kuvah'magh: B'Elanna Torres' child. Kohlar declared it to be the Day of Separation, and, despite some reluctance from his Council of Elders, ordered the ship to initiate its self-destruct sequence. Its crew, comprised of men, women and children, was beamed aboard Voyager and the ship was destroyed by a warp core breach. (VOY: "Prophecy")
|IKS Devisor • IKS Gr'oth • Kang's battle cruiser • IKS Klothos • Kohlar's battle cruiser • Kuri's battle cruiser • L'Rell's battle cruiser • Tal's flagship • Unnamed|
The designation of Kohlar's battle cruiser was misidentified in the script of "Prophecy". Writer Mike Sussman has explained the mistake in a response to an article.  He assumed that the physical D7-class model built by Greg Jein for "Trials and Tribble-ations" could be reused in this episode. However, all the effects were apparently slated to be computer-generated. To his knowledge, a CGI version of Jein's D7 did not exist at the time and it would have cost a fair amount of money to design one. Had Sussman been aware of this, he would have simply changed the script. As a result, this usage of the K't'inga-class may be justified as a transitional predecessor to the actual K't'inga-class battle cruiser in the D7 lineage.
The Star Trek Customizable Card Game gives its name as IKS Voq'leng.