Why Do So Many Cultures Have Dragons? Serpents, Storms and the Bones in the Ground

The earliest recognisable dragon is Mesopotamian. Tiamat, in the Babylonian creation epic written down around 1100 BC from older material, is the salt-water goddess who takes the form of a sea dragon, and the young god Marduk kills her with a net and arrows and makes the sky from one half of her body and the earth from the other. The pattern, a storm or sky god defeating a serpent of chaos or water, repeats across the Indo-European world: Indra kills the drought-serpent Vritra in the Vedas; Zeus destroys the hundred-headed Typhon; Thor fights the world serpent; and Apollo kills the Python at Delphi. It is old enough that linguists reconstruct a formula, the hero slays the serpent, in the language ancestral to Sanskrit, Greek and Norse, and the dragon fight may be one of the oldest stories humans have.

The creature that reached the modern imagination comes in two families that are almost opposites:

• •The western dragon: a serpent with legs, bat wings and fiery breath, living in caves and hoarding gold, an enemy to be slain by Saint George, Beowulf, Sigurd or a knight, and a symbol of the devil in Christian art
• •The eastern dragon: a long, wingless, four-legged serpent with a mane, antlers and a pearl, living in rivers, lakes and clouds, master of rain and rivers, benevolent though dangerous, and the emblem of the Chinese emperor
• •Others: Quetzalcoatl, the feathered serpent of Mexico; the rainbow serpent of Aboriginal Australia, who made the rivers; the naga of India and Southeast Asia, cobra-like guardians of water and treasure; and the Aztec, Persian and Japanese variants of each

The simplest explanation is that dragons are snakes made larger, and that humans are born prepared to notice snakes. Primates, including people with no experience of them, detect snake shapes faster than other shapes, and the anthropologist Lynne Isbell has argued that snakes were the main predator of early primates for tens of millions of years and shaped the visual system itself. A dragon is a snake with the other fears added: the teeth and claws of the big cats, the wings and talons of the eagle, the fire of the thing that destroys villages. David E. Jones, in An Instinct for Dragons, proposed exactly that composite, the three predators of ancestral primates rolled into one, which would explain why the creature turns up wherever there are people.

The second explanation is that people found the bones. Dinosaur and other fossils weather out of hillsides in China, Mongolia, the American West and Europe, and a community that dug up a skull with a metre of teeth would need a story for it. The Chinese word for dragon bones was applied to fossils used in medicine for two thousand years, and Adrienne Mayor has traced the griffin of Greek legend, a beaked, four-legged guardian of gold in Scythia, to the Protoceratops skeletons that erode from the gold-bearing sands of the Gobi. In medieval Europe, mammoth skulls with their single nasal opening were taken for cyclops heads and fossil bones were hung in churches as the remains of dragons; a specimen in Klagenfurt cathedral, the model for the town's dragon statue of 1590, is a woolly rhinoceros skull.

The eastern dragon in particular is a creature of water and weather, and its ancestor may be the river itself: sinuous, powerful, life-giving and capable of drowning a province, honoured with offerings and blamed for floods. The Chinese dragon rises from the lake in spring, brings the rains, and returns in autumn, which is the agricultural year in the shape of an animal, and dragon-boat races and dragon dances are prayers for rain. Storms supplied the rest: lightning is the flash of the dragon's pearl, the waterspout is a dragon drinking from the sea, and a comet is a dragon crossing the sky. The western dragon's fire may be a memory of the same weather, or of the flammable gas that seeps from swamps and burns at night.

Dragons appear in the myths of nearly every culture because several things push the same way: an inherited alertness to snakes that mythology enlarged with the teeth, claws and wings of other predators; fossil bones that needed an explanation; rivers, storms and weather personified as a great serpent; and, in the Indo-European world, a story of a storm god slaying the serpent of chaos that is older than writing. The western dragon became a hoarding monster to be slain and the eastern one a benevolent master of rain, and both descend from the same ingredients.