Zhang Guolao

Zhang Guolao is the one member of the group whose image is instantly identifiable and slightly absurd: a very old man riding a white mule while facing its tail. The explanation offered is that the mule travels enormous distances in a day, tens of thousands of li, and that when the journey is over he folds it flat like a sheet of paper and puts it away in his wallet, then sprinkles it with water from his mouth to bring it back. Nobody in the tradition treats the backwards riding as needing further justification, and the usual gloss is that looking behind rather than ahead is the correct posture for someone who has seen enough.

His instrument is the fish drum, a length of bamboo closed at one end and struck or beaten with two rods, an instrument associated with itinerant storytellers, and he is patron of that trade.

Unlike most of the group he is anchored to something documented. The Tang official histories record a recluse called Zhang Guo who was summoned to the court by the emperor Xuanzong in the eighth century, was questioned about his age and the means of his longevity, declined honours and returned to the mountains. That is a plain record of an unusual man. The immortal Zhang Guolao, with the folding mule and the great age, is what the tradition made of him afterwards, and the atlas records the two layers separately.

The commonest use of Zhang Guolao in ordinary religious life has little to do with his stories. He is petitioned for sons, and the standard image of him, printed and hung at weddings, shows him mounted and presenting an infant to a couple.

How an aged hermit became the bringer of children is not fully explained by anything in the narrative material, and the tradition does not appear to have felt the need. Popular cult attaches functions to figures for reasons that are often iconographic rather than narrative: an old man of enormous longevity is an auspicious presence at the beginning of a family line, and the picture works whether or not a story supports it.

The tests he is put through in the fuller accounts are of a piece with the group's humour. Summoned to court, he is served poisoned wine to see what he is, drinks it, falls asleep, and wakes complaining only that his teeth have gone black; he then knocks them out and grows a new set. Offered an imperial princess in marriage he refuses and vanishes. When the emperor sends a man to fetch him again he dies on the spot, is buried, and the coffin is found empty.

The Eight Immortals appear together far more often than singly, in the eight-crossing-the-sea story and on birthday and New Year decoration, and Zhang Guolao's mule is usually how a viewer picks the group out of a crowded design.