Among the Eight Immortals, Zhang Guolao, Zhongli Quan and Lü Yan are the only ones who appear in historical records as genuine figures in society at specific times and places.

[1] Zhang was a Taoist fangshi (translated as "occultist-alchemist") who lived as a hermit on Zhongtiao Mountain (中條山; southeast of present-day Yongji, Shanxi) in Hengzhou (恆州) during the Tang dynasty.

[7] Since he represents old age, in the Taoist fengshui tradition, a picture or statue of him can be placed in the home or bedroom of an elderly person to help bring them a long life and a good, natural death.

[7] Zhang was known for wandering between the Fen River and Qin territories during his lifetime and was known to travel at least a thousand li per day on a white donkey or mule.

[2] In 735, during the reign of Emperor Xuanzong of the Tang dynasty, Zhang was called to Luoyang, where he was elected as the chief of the Imperial Academy, with the honorable title "Very Perspicacious Teacher."

Having been promised by Emperor Xuanzong, Ye Fashan then said: "Zhang Guolao is a white spiritual bat which came out of primeval chaos."

[2] In the television show Jackie Chan Adventures, Zhang Guolao is the Immortal who sealed away Po Kong, The Mountain Demon.