The Star of Kahless was a medal awarded to Klingon individuals when they joined the Order of Kahless.
Emperor Reclaw posthumously awarded Kam'pok the Star of Kahless prior to the Dark Time. (ST reference: The Klingon Art of War)
In 2375, Martok was admitted into the Order of Kahless and had the Star of Kahless awarded to him by Gowron in a ceremony aboard Deep Space 9. (DS9 episode: "When It Rains...")