In Klingon traditional history, Molor was a hated tyrant who ruled Qo'noS some time in the 9th century. Molor was said to be so strong that no man could oppose him, except one: Kahless the Unforgettable, who, together with the Lady Lukara, fought a pitched battle in the Great Hall of the city of Qam-Chee against the soldiers of Molor. While the rest of the city's garrison fled before Molor's five hundred soldiers, Kahless and Lukara stood their ground and defeated the forces. (DS9: "Looking for par'Mach in All the Wrong Places") Kahless killed Molor with a newly-forged sword, which came to be known as the Sword of Kahless, and founded the Klingon Empire, becoming the greatest warrior in Klingon history. (DS9: "The Sword of Kahless") Molor's defeat was celebrated annually with the observance of the Kot'baval Festival. (TNG: "Firstborn")
The exact time period in which Kahless, and therefore also Molor, lived has repeatedly been described with differing numbers. In DS9: "Looking for par'Mach in All the Wrong Places" taking place in 2373, Worf enthusiastically mentioned the events in Qam-Chee to have happened "a thousand years ago." This would appear to be somewhat of a contradiction as TNG: "Rightful Heir" states, that the monks on Boreth have been awaiting Kahless' return for 15 centuries, i.e. 500 years longer. Either Worf "rounded" the number of years in his enthusiasm, or Molor and Kahless were at least five hundred years old, which while the maximum life span for Klingons has never been clearly defined, seems to be without precedent. Another solution would be that Worf counted in Klingon years, as 2373 corresponds to the Year of Kahless 999. This would also be in accord with the Sword of Kahless being dated to an age of 1,400 years in DS9: "The Sword of Kahless". Furthermore, a scene cut from "Rightful Heir" had Data specify Kahless' death as 1547 years ago, which would place it in 822 AD.