With fire and steel did the gods forge the Klingon heart. So fiercely did it beat, so loud was the sound, that the gods cried out, 'On this day we have brought forth the strongest heart in all the heavens. None can stand before it without trembling at its strength.' But then the Klingon heart weakened, its steady rhythm faltered and the gods said, 'Why have you weakened so? We have made you the strongest in all of creation. And the heart said: 'I am alone.' And the gods knew that they had erred. So they went back to their forge and brought forth another heart. But the second heart beat stronger than the first, and the first was jealous of its power. Fortunately, the second heart was tempered by wisdom: If we join together, no force can stop us.' And when the two hearts began to beat together, they filled the heavens with a terrible sound. For the first time, the gods knew fear. They tried to flee, but it was too late. The Klingon hearts destroyed the gods who created them and turned the heavens to ashes. To this very day, no one can oppose the beating of two Klingon hearts.
I didn't see this thread until now, and I was about to quote this very dialog. It's part of the Klingon marriage ceremony, recited in DS9's "You Are Cordially Invited."
In the context of the Trek universe, in which advanced aliens did indeed muck about on various primitive planets thousands of years ago, it is quite possible that this was based on something that actually happened in Klingon history.
I've long wondered if the reference was to the Klingons throwing off the oppression and enslavement forced on them by the Hur'q. The Hur'q fleeing with the sword of Kahless is the sort of thing oppressors do when their yoke is thrown off.
I don't think it was the same as the Hur'q. The Hur'q were described as invading a Klingon homeworld which already had an established society and history, centuries after the time of Kahless. They pillaged and plundered the Klingon homeworld. They are attested to in actual history, and their DNA is identifiable. But the gods the Klingons claim to have destroyed were beings described in vague legendary terms, and they are remembered as having created the Klingons from scratch.
Kor