There is a legend. At the beginning of Zhou Dynasty (about 17 or 16 century B.C.), or someone says it happened in King Zhoulie Period (about 4 century B.C.), there was a person named kuangsu. He practiced austerities in Mountain Lushan. It is said that kuangsu's style name was “Junxiao”, some books called him “Kuangyu” or “Kuangxu”, and style name was “Zixiao”, but “Yu” sounds more reasonable by the look of China's traditional name and antithetical couplet justice of the word, so “Su” and “Xu” was the device sound of his name by rumors. But name that spread generally to claim it is “Su”, and very few people know the name “Yu” now. For being convenient, here we follow the call which people know well. In addition, people claim “Kuangsu” as “Lusu” because of the famous mountain. Regard name of the place as surname also accord with the ancient convention. As for he exact surname, we need not investigate, and have record to investigate. It is said Kuangsu' practicing austerities in Mountain Lushan was learnt by imperial court. Then the emperor invited him to come out of retirement and take up an official post to aid time and again, but Kuanhsu refused the invitation time and again by slipping into the remote mountains. Later, Kuangsu diappeared without a trace. Someone says that he has gone to become the celestial being. This is a baseless gossip naturally. Later on people beautified story of Kuangsu, and called the place where he stayed “the immortal's hut”, and name of Mountain Lushan come out. Also people name Lushan after Kuangsu's surname as "kuangshan". Arrived the Song dynasty, for avoiding using the same word as the name of Song emperor, people renamed it “kangshan”.
Another kind of legend, in Zhou Wuwang's time, there was a person named “fangfu”. He entered the mountain with Lier together, riding white donkey, to make pills of immortality. They both became immortal later, and only left an empty hut in the mountain. People called this empty mountain “Mountain Lushan”. Also people named the mountain after Fangfu's givename as “Fushan”. But king Wu and Lier were not at the same time, so this is equally a fairy tale.
The third kind of legend is still gentleman Kuanglu's story. But time is relatively late. Plots are a bit different too. It says to be kuanglu's father, the east wild king. Once he with Wurui together, assisted a ruler in governing a country Liu Bang calm down the world. The east wild king unfortunatly died midway. Imperial court for cite exploit of him, seal son of the east wild king the land named wuyang (it is a part of Duyang county now). Kaunglu had six brothers. They all interested in Taoism, and practiced austerities in Mountain Wuyang. Later people called the mountain where they stayed “Mountain Lushan”.