Two Christian monks smuggled silk worms out of China in bamboo canes. Those worms were used to give the Byzantine Empire a trade monopoly in Europe, which became the foundation of their economy for the next 650 years
In the mid-6th century CE, two Christian monks, with the support of the Byzantine emperor Justinian I, carried out a successful smuggling of worm eggs into the Byzantine Empire, which led to the establishment an indigenous Byzantine silk industry. The acquisition of worms from China allowed the Byzantines to have a monopoly of silk in Europe.
Silk, which was first produced sometime during the fourth millennium BC by the Chinese, was a valuable trade commodity along the Silk Road. By the first century CE, there was a steady flow of silk into the Roman Empire. With the rise of the Sassanid Empire and the subsequent Roman–Persian Wars, importing silk to Europe was increasingly difficult and expensive. The Persians strictly controlled trade in their territory and would suspend trade in times of war. Consequently, the Byzantine 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 the Crimea, and one to the south via Ethiopia. The failure of these efforts led Justinian I to look elsewhere.
Shortly after the expedition there were silk factories in Constantinople, Beirut, Antioch, Tyre, and Thebes. The acquired worms allowed the Byzantine Empire to have a silk monopoly in Europe. The acquisition also broke the Chinese and Persian silk monopolies. The resulting monopoly was the foundation for the Byzantine economy for the next 650 years until its demise in 1204. Silk clothes, especially those dyed in imperial purple, were almost always reserved for the elite in Byzantium, and their wearing was codified in sumptuary laws