China is thought to have initiated formal contact with the "Western Regions" in the 2nd century BC, with the embassy of Zhang Qian.
The Roman historian Florus describes the visit of numerous envoys, including Seres (Chinese, or, more probably Central Asians), to the first Roman Emperor Augustus, who reigned between 27 BC and 14:
"Even the rest of the nations of the world which were not subject to the imperial sway were sensible of its grandeur, and looked with reverence to the Roman people, the great conqueror of nations. Thus even Scythians and Sarmatians sent envoys to seek the friendship of Rome. Nay, the Seres came likewise, and the Indians who dwelt beneath the vertical sun, bringing presents of precious stones and pearls and elephants, but thinking all of less moment than the vastness of the journey which they had undertaken, and which they said had occupied four years. In truth it needed but to look at their complexion to see that they were people of another world than ours."[1]
In 97 AD, the Chinese general Ban Chao unsuccessfully tried to send an envoy to Rome.[2][3] Several alleged Roman emissaries to China were recorded by ancient Chinese historians. The first one on record, supposedly from either the Roman emperor Antoninus Pius or the later emperor Marcus Aurelius, arrived in 166.[4][5]The Hou Hanshu records the arrival of Roman envoys, by sea to Chinese territory in what is now North Vietnam in 166 AD, presumably from either the Roman emperor Antoninus Pius or the later emperor Marcus Aurelius. The text specifically states that it was the first time there had been direct contact between the two countries.[6]
The trade relations between Rome and the East, including China, were described in the Periplus of the Erythraean Sea in the 1st century AD
The indirect exchange of goods on the land (the so-called Silk Road) and sea routes included Chinese silk, Roman glassware, high-quality cloth, spices, perfumes, gems, etc.[7]
The Liangshu records the arrival in 226 AD of a merchant from the Roman Empire (Da Qin) at Jiaozhi (near modern Hanoi). The Prefect of Jiaozhi sent him to Sun Quan [the Wu (kingdom) emperor], who asked him for a report on his native country and its people. An expedition was mounted to return the merchant to along with 10 female and 10 male "blackish coloured dwarfs" he had requested as a curiosity and a Chinese officer who, unfortunately, died enroute.[8]
In classical sources, the problem of identifying references to ancient China is exacerbated by the interpretation of the Latin term "Seres" whose meaning fluctuated and could refer to a number of Asian people in a wide arc from India over Central Asia to China.[9] In Chinese records, the Roman Empire came to be known as "Da Qin", Great Qin, apparently thought to be a sort of counter-China at the other end of the world.[10] According to Pulleyblank, the "point that needs to be stressed is that the Chinese conception of Da Qin was confused from the outset with ancient mythological notions about the far west".[11]