Some 15,000 years ago, in what is now the Dordogne region of France, someone – man or woman, we don’t know – crawled hundreds of metres through a dark underground passage no more than one metre high. Then he or she scratched a few lines on a bulge of rock. Suddenly, the rock was transformed: an image of a horse appeared. No one else could witness the appearance of the animal: only one person at a time could fit into the confined space. Then he or she retreated back down the passage to the world of light.

A few kilometres away a different scene was enacted. In a large subterranean chamber a number of people gathered to mix paint and to erect scaffolding. Then, with broad sweeps and different colours, they created a procession of horses, aurochs, deer and, hidden amongst them, a solitary bear.

The diversity of Upper Palaeolithic imagery is staggering. The period and its efflorescence of art lasted from about 35,000 to 10,000 years ago. Today we are still able to appreciate these ancient accomplishments because