- You may also be looking for Kronos One (mirror).
The IKS Kronos One was a K't'inga-class battle cruiser that served as the flagship of the Klingon Chancellor during the 23rd century.
In 2293, Kronos One ferried Chancellor Gorkon and his representatives to a rendezvous with the USS Enterprise-A, which was to escort the vessel to Earth for a peace conference between the United Federation of Planets and Klingon Empire. The ship was heavily damaged by a surprise attack, initially believed to be from the Enterprise, and was boarded by two assassins from the Enterprise who killed Gorkon. It was later discovered that the Enterprise had been framed for the attack by a cloaked Bird-of-Prey as part of a wide conspiracy to sabotage the peace talks between the two regional powers. (Star Trek VI: The Undiscovered Country)