Silk was first made by the Chinese about 4,000 years ago. Silk thread is made from the cocoon of the silkworm moth (Bombyx mori), a small moth whose caterpillar eats the leaves of the mulberry tree. The white cocoon is dropped into boiling water, and silk thread is unwound. Each cocoon yields about 500 to 1,200 yards of silk.
According to Chinese legend, the first silk thread was made when a Chinese Empress was sitting under a mulberry tree, and a cocoon fell into her tea; she noticed the strong, silky threads of the cocoon uncoiling. It is said that Empress Si-Ling-Chi, the wife of Emperor Huang-ti then experimented with silkworms and developed the use of silk in weaving around 2400 B.C.
Silk soon became very important to the Chinese economy, and it remained a Chinese secret for thousands of years, due in part to the Great Wall of China. The Chinese traded precious silk fabric to the rest of the world via the Silk Road, an overland trade route from China through the deserts of Central Asia to the West. The secret methods of raising silkworms and making silk were brought to Japan in the 3rd century A.D.