Missive that went missing for centuries

Another outstanding exhibit from Hotan, the Buddhist Golden Light Sutra written in Khotanese, can also be dated back to the 8th to 9th centuries. Buddhism was a crucial medium for cultural communication of the time, Liu says.

"Many Buddhist sutras were brought in from India and translated into Chinese in Chang'an (what is today Xi'an, Shaanxi province). However, their influence expanded westward again along the Silk Road."

The Biography of Master Sanzang, written in Huihu (ancient Uygur) language, found in Xinjiang, and which hails the great Tang Dynasty (618-907) monk's contribution to Buddhism, is also on display in the exhibition

When it comes to the spread of Buddhism along the Silk Road, Dunhuang, Gansu province, probably offers an incomparable reference for today's studies.

In 1900, 60,000 ancient documents in many different languages were discovered in one of the Mogao Caves in Dunhuang, also known as the "library cave". The encyclopedic manuscripts spanned almost a millennium, and religion plays a key theme in the documents.

Many Dunhuang manuscripts were snatched and taken to the West, but the National Library of China is fortunate to have 16,000 of those that were left. A few of the most precious ones are now publicly shown.

Vinaya (Buddhist principles) in Four Parts, written in 417, is the earliest known work among Dunhuang manuscripts now held in China. In a post script to the Lotus Sutra, written in 968, a monk vividly describes his difficulties in traveling to India, which Liu says "has filled many voids in studies of extant files".

A scripture of Manichaeism, a religion whose genesis was in what is today Iran in the third century, and which once held wide sway across Eurasia, is also among the exhibited manuscripts.

Only three scriptures of Manichaeism were found in Dunhuang, the other two being in France.

"These documents marking the history of the Silk Road are like windows of accessibility for academia worldwide," Liu says.

"Western scholars can easily find familiar cultural elements that echo their own. That will also inspire today's people to think of modern issues from a cross-cultural perspective."