Gorkon was the Klingon chancellor who opened peace talks with the Federation after the Praxis disaster and was assassinated before they could be completed.
Gorkon led the Klingon High Council in 2293 when the explosion of the moon Praxis crippled the Empire's energy production and poisoned its atmosphere. Facing ruin, he took the bold step of seeking peace with the Federation, ending decades of hostility.
Spock helped to arrange the talks, and the Enterprise under James T. Kirk was ordered to escort Gorkon's battle cruiser Kronos One to Earth. After a tense dinner aboard the Enterprise, Kronos One was hit by torpedoes that seemed to come from the Enterprise, and two assassins in Starfleet uniforms beamed aboard and shot Gorkon. Despite McCoy's efforts, the chancellor died, and Kirk and McCoy were arrested for the crime. The killing was in fact the work of conspirators from both sides, including his own chief of staff Chang.
Gorkon's vision outlived him. His daughter Azetbur took over as chancellor and continued the process he began, leading to the Khitomer Accords and the long era of Klingon and Federation peace.