Xiang An, originally the King of Northern Chu, was a great ruler of the Central Plains during the Chu-Han Contention at the end of Qin and beginning of Han. He was a king praised even by his rival Liu Bang, a wise king beloved by the people of Northern Chu, and also...
the King Yama of legend.
Yet the earliest tales about him actually called him the "Lord of Mount Tai," that is, the [Great Emperor of the Eastern Peak].
This originated from an anecdote from Xiang An's lifetime.
After returning from one campaign, Xiang An passed through Mount Tai and suddenly acted on a whim. He left all the soldiers accompanying him, along with his beloved horse Surging Wave Gallop, at the foot of the mountain and climbed Mount Tai alone. There, he ate fruit when hungry, drank dew when thirsty, and whenever exhaustion overtook him at night, he simply found a cave and went to sleep.
Several days later, Zi Juan, the great general of Northern Chu, arrived at the foot of the mountain. Xiang An was nowhere to be seen; all she found were the soldiers Xiang An had left behind and Surging Wave Gallop, who was even leisurely grazing on grass.
Just as Zi Juan was frantic with worry, Xiang An appeared, covered in grass, mud, and water yet positively radiant. Then he declared his intent to perform the Feng and Shan sacrifices on Mount Tai.
The Feng and Shan sacrifices on Mount Tai were something only the sovereign of the Central Plains could perform, while Xiang An was merely the King of Northern Chu.
Without question, Xiang An's actions appeared arrogant and presumptuous in the eyes of the world.
Only Zi Juan and Liao Ye, who remained constantly at Xiang An's side, knew what he