Of all the alien species in the Star Trek universe, the Klingons are one of the most culturally complex. They have an elaborate belief system, The Way of the Warrior, that dictates how they approach every major milestone in life as well as death. Those belief systems are based on an immense canon of mythology about how the Klingons came to be, the great battles their ancestors fought, and the heroes of those battles. Some of these myths were written down, but for the most part, Klingons passed on their belief systems through storytelling and song.