During the Han Dynasty, people believed the tiger to be the king of all beasts. According to legend the tiger's tail would turn into white when it reached the age of 500 years. In this way, the white tiger became a kind of mythological creature. It was said that the white tiger would only appear when the emperor ruled with absolute virtue, or if there was peace throughout the world. Because the color white of the Chinese five elements also represents the west, the white tiger thus became a mythological guardian of the west.
In some legends of the Tang Dynasty's general Xue Rengui, he is said to be the reincarnation of the White Tiger's Star, and his archenemy, the Liao Dynasty's prince He Suwen is the reincarnation of the Azure Dragon's Star.