Silk roots: How Eastern fortunes were made, thanks to a moth

Yangshao people, who lived between 5000BCE and 2000BCE along the Yellow River Valley, are thought to have been the first ever to have practised China's most lucrative long-term secret – silkworm cultivation.

Silk is extraordinary stuff. It is entirely natural. It reflects the light, giving it a shiny and glamourous appearance. Above all, it is amazingly strong. In fact, silk is the strongest natural fibre known to man. Insects manufacture silk as a kind of miniature binding rope to protect their larvae. Gradually, as the larvae hatch, they gnaw through the silk rope to emerge out of the cocoon as butterflies or moths. Some adult insects use silk for other purposes. For instance, spiders use it to make webs to catch prey.

Legend has it that the magical properties of silk were first discovered by Leizu, wife of the Yellow Emperor, who reigned from 2697BCE to 2598BCE. While out for a walk, she is said to have noticed something wrong with the Emperor's mulberry trees. She found that thousands of caterpillars were munching their way through the leaves, causing a great deal of damage. She collected some of the cocoons from which the caterpillars came and then sat down to drink a cup of tea.

While she was taking a sip, a moth larva accidentally dropped into the steaming water and a fine thread started to appear, unwinding itself from around the cocoon. Leizu found she could wrap this fine, strong cord around her finger. Inspiration struck.

She persuaded the Emperor to plant a whole grove of mulberry trees, and then worked out how to harness silk by reeling it into long threads that could then be woven into shiny pieces of precious cloth.

The practice of what is now called sericulture, the deliberate farming of a type of caterpillar called Bombyx mori, brought enormous wealth and prosperity to China. For as long as 3,000 years, Chinese farmers and tradespeople have profited by trading silk with other civilisations who marvelled at its glistening appearance. Plastic man-made alternatives, in the form of satin, nylon and acrylic, weren't concocted until the Second World War ( see Part 13).

Silk was the primary cause for the development of a series of overland trade routes that later become known as the Silk Road. By the time of the Roman Empire (44BCE-476CE), silk was in huge demand by Mediterranean people. Its fine texture and semi-transparent shimmer made it one of the great luxuries of the ancient world.