The IKS Buruk was the Klingon Bird-of-Prey that brought Gowron to the rite of succession in 2367, when he and Duras contended to lead the High Council after K'mpec's death.
The Buruk appears in the Next Generation episode Reunion. It arrives alongside the Vorn, the ship of Duras, to meet the Enterprise-D and the cruiser of Chancellor K'mpec, who has been slowly poisoned and has asked Captain Picard to act as arbiter of succession.
Gowron, then an outsider who had often challenged the council, uses the ship as his base during the proceedings. He is seen trying to bribe K'Ehleyr for her support, and he and Duras are both delayed by Picard's insistence on the long traditional form of the rite while the bombing of the Sonchi ceremony is investigated.
After Worf kills Duras aboard the Vorn, Gowron is left unopposed and goes on to become chancellor.