When Did People Start Making Silk?

Silk was an expensive luxury in ancient times, worn only by elites: “The Seres [Chinese] are famous for the wool of their forests [silk]... which, when woven into cloth, is sold at such a price that it drains the wealth of our empire,” wrote the Roman author Pliny the Elder in about A.D. 70.

Even a small piece of woven silk needed the thread from thousands of silkworm cocoons, and the ancient Chinese dominated its production—mainly due to their intensive cultivation of a domesticated silk moth species called Bombyx mori, which produced cocoons several times larger than those of their wild cousins.

Silk was prized then, as now, because of its exclusivity and rarity; its distinctively shimmering appearance; its ability to take dye well; its warmth in cold and coolness in heat; and its strength and extreme lightness, which makes it comfortable to wear. "Silk also has this very ethereal quality to it—it's very magical," says biologist Aarathi Prasad, author of Silk: A World History (2024, William Morrow) and a researcher at University College London.

Chinese legend says that silk was discovered in about 2700 B.C. by the Empress Leizu, wife of the mythical Yellow Emperor, when she sipped tea in the shade of a mulberry tree—the exclusive food of Bombyx mori. According to the legend, a silkworm cocoon fell into her cup and unraveled in the hot water as a shimmering thread, revealing the secret. But experts think this never happened. "Silk was such an exotic, prestigious and expensive product that there were always a lot of myths connected with it," says Marie Louise Nosch, who studies ancient textiles at the University of Copenhagen.

Excavations in central China have revealed traces of silk from up to 8,500 years ago, and archaeologists think people there began farming Bombyx mori silkworms between about 5,000 and 4,100 years ago—long before the development of Chinese writing in about 1200 B.C.

It was said that China fiercely guarded its silk secrets, but Bombyx mori seems to have spread into neighboring regions throughout antiquity, Nosch says. Prasad adds that ancient people in places like Greece and Anatolia were already making small amounts of silk from the cocoons of wild silkworms, but Bombyx mori was a technological breakthrough. "The innovation was that the Chinese had bred these special eggs that everyone wanted," she says.

Both Prasad and Nosch also doubt a story from Byzantine historian Procopius of Caesarea, who wrote in the sixth century that two Christian monks smuggled the eggs of Bombyx mori from Asia in about A.D. 550. According to Procopius, Emperor Justinian hoped to break a Persian monopoly on the trade of silk along the Silk Roads that carried the luxurious fabric from China west into Europe. On his orders, the monks traveled to the region and smuggled out silkworm eggs in a bamboo walking stick, returning to Constantinople about two years later.

But this, too, almost certainly never happened, Prasad says. It is extremely unlikely that silkworm eggs could have survived for so long. Instead, it seems Bombyx mori arrived in the Byzantine Empire through regular trade. "There was a lot of movement of people [but] there would have been no monks stealing cocoons from China," she says.

China's early dominance of the silk industry was also due to the scale of its efforts. Tens of thousands of silkworms could be farmed on just a few mulberry trees, and their cocoons sold to specialist workers who boiled and sorted them. Later, tiers of artisans unwound the cocoons to make thread, wove the thread into cloth, dyed it, embroidered it and finally traded the finished silk to buyers.

"A lot of places were cottage industries… but there were many, many of them," Prasad says. Records indicate that China produced more than 20,000 pounds of woven silk each year under the Han Dynasty, between 202 B.C. and A.D. 220. Meanwhile, silk that traveled along the Silk Roads to the Roman Empire was worth its weight in gold, and the Roman Senate passed sumptuary laws to limit its use, which it saw as decadent and an economic threat.

Bombyx mori silk produced in the Byzantine Empire became an industrial rival to Chinese silk after the sixth century, especially in the imperial cities of Thessaloniki, Corinth and Constantinople. Bombyx mori had reached Sicily and Muslim Spain by about A.D. 900, Nosch says, and it spread to Venice and other Italian city states by about the 12th century, eventually fueling a global silk boom that continues to this day.

Prasad thinks silk also spread because it was believed to have medicinal properties. Whether it did or not, this perception helped silk’s popularity. Prasad notes that William Shakespeare promoted this belief in "A Midsummer Night’s Dream," when it’s suggested that a fairy named Cobweb—that is, spider silk—has healing magic. Wound dressings were often made from silk, and people once drank silkworm cocoon elixirs for their health. “There were all sorts of uses for it,” Prasad says.