Silk was first produced sometime during the third millennium BCE by the Chinese. By the first century CE, there was a steady flow of silk into the East Roman Empire. With the rise of the
Sassanid Empire and the subsequent
Roman–Persian Wars, importing silk to Europe became increasingly difficult and expensive. The Persians strictly controlled trade in their territory and would suspend trade in times of war. Consequently, the East Roman Emperor
Justinian I tried creating alternative trade routes to
Sogdiana, which at the time had become a major silk-producing centre: one to the north via
Crimea, and one to the south via
Ethiopia. The failure of these efforts led Justinian I to look elsewhere since demand for this luxury good was high, even within his inner circle. File:Justinian Byzanz.png|565AD. East Roman Empire, blue and purple; Sassanid Empire in yellow. Sassanid vassals, in orange, encompassing the
Persian Gulf to the south, and reaching the
Indus River in the southeast and the
Kingdom of Khotan in the northeast (both silk-growing areas). File:Map of Sogdia.jpg|
Sogdiana, located in
Central Asia north of the Sassanid states. Silk was also produced in the
Kingdom of Khotan (east of Sogdiana) at this time, and in the
Indian subcontinent, east of the Sassanid Empire File:Northern and Southern Dynasties 560 CE.png|Silk production also occurred in these areas of
East Asia in 560AD, in the
Northern and Southern dynasties or
Six Dynasties period ==Expedition==