This is an edited version of a Wikipedia article on the transmission of Buddhism along the Silk Road.
Central Asian Monks
The Silk Road transmission of Buddhism to China started in the 3rd century BCE during the reign of the first emperor of China, Qin Shihuang. The first documented translation efforts by Buddhist monks were in the 2nd century CE, probably as a consequence of the expansion of the Kushan Empire into the Chinese territory of the Tarim Basin.
From the 4th century onward, with Fa-xian‘s pilgrimage to India (395–414), and later Xuan-zang’s (629–644), Chinese pilgrims too started to travel by themselves to northern India in order to get improved access to original scriptures. The Silk Road transmission of Buddhism began to decline around the 7th century with the rise of Islam in Central Asia.
Earliest historical evidence
According to recent research in China, Buddhism had already been established there by the reign of the first emperor, Qin Shihuang, who is said to have suppressed Buddhism and Buddhist temples in the same way he did other philosophical schools. Han Wei, a noted researcher from the Shaanxi Provincial Institute of Archaeology, found evidence for this in Records of the Grand Historian, along with corresponding historical, linguistic, and archaeological evidence. According to this study, Buddhism was already popular in the interior regions of China by the time its suppression began in 213 BCE.
The 1st century BCE Records of the Great Historian tells of the travels of the Chinese explorer Zhang-qian to Central Asia around 130 BCE. He reports about a country named Shendu (India), whose peaceful Buddhist ways are mentioned in writing in the 1st century CE Han history, the Hanshu. Chinese murals in the Tarim Basin city of Dun-huang show Han Wu-di (156–87 BCE) worshiping Buddhist statues, “golden men brought in 120 BCE by a great Han general in his campaigns against the nomads”.
However, there is no such mention of Han Wu-di worshiping the Buddha in Chinese historical literature. The Hou Hanshu also records the visit to the Chinese capital in 2 BCE of Yuezhi envoys, who gave oral teachings on Buddhist sutras to a student, suggesting that some Yuezhi had already started to disseminate the Buddhist faith in eastern Asia during the 1st century BCE. The Hou Hanshu then describes a questionable legend about the encouragement of Buddhism around 70 CE by Emperor Ming (58–75 CE):
There is a current tradition that Emperor Ming dreamed that he saw a tall golden man the top of whose head was glowing. He questioned his group of advisors and one of them said: “In the West there is a god called Buddha. His body is sixteen chi high (3.7 metres or 12 feet), and is the colour of true gold.” The Emperor, to discover the true doctrine, sent an envoy to Tianzhu (Northwestern India) to inquire about the Buddha’s doctrine, after which paintings and statues of the Buddha appeared in the Middle Kingdom.
Silk Road Peoples
The first documented translation of Buddhist scriptures into Chinese occurs in 148 CE with the arrival of the Parthian prince-turned-monk, An Shi-gao. He worked to establish Buddhist temples in Loyang and organized the translation of Buddhist scriptures into Chinese, testifying to the beginning of a wave of Central Asian Buddhist proselytism that was to last several centuries. An Shi-gao translated Buddhist texts on basic doctrines, meditation and Abhidharma. An Xuan, a Parthian layman who worked alongside An Shigao, also translated an early Mahāyāna Buddhist text on the bodhisattva path.
Mahāyāna Buddhism was first widely propagated in China by the Kushan monk Lokakṣema (active ca. 164–186 CE), who came from the ancient Buddhist kingdom of Gandhāra. Lokakṣema translated important Mahāyāna sūtras such as the Aṣṭasāhasrikā Prajñāpāramitā Sūtra, as well as rare, early Mahāyāna sūtras on topics such as samādhi and meditation on the buddha Akṣobhya. These translations from Lokakṣema continue to give insight into the early period of Mahāyāna Buddhism.
Central Asian missionaries
In the middle of the 2nd century CE, the Kushan empire under king Kaniṣka expanded into Central Asia and went as far as taking control of Kashgar, Khotan and Yarkand, in the Tarim Basin, modern Xin-jiang. As a consequence, cultural exchanges greatly increased, and Central Asian Buddhist missionaries became active shortly after in the Chinese capital cities of Loyang and sometimes Nanjing, where they particularly distinguished themselves by their translation work. They promoted both Hīnayāna and Mahāyāna scriptures. Thirty-seven of these early translators of Buddhist texts are known.
Central Asian missionnary efforts along the Silk Road were accompanied by a flux of artistic influences, visible in the development of Serindian art from the 2nd to the 11th century CE in the Tarim Basin, modern Xin-jiang.
Serindian art often derives from the Greco-Buddhist art of the Gandhāra district of what is now Pakistan, combining Indian, Greek and Roman influences.
Highly sinicized forms of this syncretism can also be found on the eastern portions of the Tarim Basin, such as in Dun-huang.
Silk Road artistic influences can be found as far as Japan to this day, in architectural motifs or representations of Japanese gods (see Greco-Buddhist art).
Chinese Pilgrims to India
According to Chinese sources, the first Chinese to be ordained was Zhu Zixing, after he went to Central Asia in 260 to seek out Buddhism. It is only from the 4th century CE that Chinese Buddhist monks started to travel to India to discover Buddhism first-hand. Fa-hsien‘s pilgrimage to India (395–414) is said to have been the first significant one. He left along the Silk Road, stayed six years in India, and then returned by the sea route. Tens of Chinese monks, possibly hundreds of them, visited India during that period.
The most famous of the Chinese pilgrims is Xuan-zang (629–644), whose large and precise translation work defines a “new translation period”, in contrast with older Central Asian works. He also left a detailed account of his travels in Central Asia and India.
Buddhism in Central Asia began to decline in the 7th century following the incursion of the Muslim Caliphate. The vigorous Chinese culture progressively absorbed Buddhist teachings until a strongly Chinese particularism developed. However, Central Asian Buddhist monks from the Tarim Basin and East Asian Buddhist monks appear to have maintained strong exchanges until around the 10th century, as shown by frescoes from the Tarim Basin.