Given textual and archaeological evidence, it is thought that thousands of Europeans lived in Imperial China during the Yuan dynasty. These were people from countries traditionally belonging to the lands of Christendom during the High to Late Middle Ages who visited, traded, performed Christian missionary work, or lived in China. This occurred primarily during the second half of the 13th century and the first half of the 14th century, coinciding with the rule of the Mongol Empire, which ruled over a large part of Eurasia and connected Europe with their Chinese dominion of the Yuan dynasty. Whereas the Byzantine Empire centered in Greece and Anatolia maintained rare incidences of correspondence with the Tang, Song, and Ming dynasties of China, the Holy See sent several missionaries and embassies to the early Mongol Empire as well as to Khanbaliq (modern Beijing), the capital of the Mongol-led Yuan dynasty of China. These contacts with the West were preceded by rare interactions between the Han dynasty and Hellenistic Greeks and Romans.

Mainly located in places such as the Yuan capital of Karakorum, European missionaries and merchants traveled around various parts of the Yuan dynasty and other Mongol-ruled khanates during a period of time referred to by historians as the "Pax Mongolica". Perhaps the most important political consequence of this movement of peoples and intensified trade was the Franco-Mongol alliance, although the latter never fully materialized, at least not in a consistent manner.Atwood, Christopher P. (2004), Encyclopedia of Mongolia and the Mongol Empire, New York: Facts on File, Inc., p. 583, . The establishment of the Ming dynasty in 1368 and reestablishment of ethnic Han rule led to the cessation of European merchants and Roman Catholic missionaries living in China. Direct contact with Europeans was not renewed until Portuguese explorers and Jesuit missionaries arrived on Ming China's southern shores in the 1510s, during the Age of Discovery.

The Italian merchant Marco Polo, preceded by his father and uncle Niccolò and Maffeo Polo, traveled to China during the Yuan dynasty. Marco Polo wrote a famous account of his travels there, as did the Franciscan friar Odoric of Pordenone and the merchant Francesco Balducci Pegolotti. The author John Mandeville also wrote about his travels to China, but he may have based these on preexisting accounts. In Khanbaliq, the Roman archdiocese was established by John of Montecorvino, who was later succeeded by Giovanni de Marignolli. Other Europeans such as André de Longjumeau managed to reach the eastern borderlands of China in their diplomatic travels to the Yuan imperial court, while others such as Giovanni da Pian del Carpine, Benedykt Polak, and William of Rubruck traveled instead to Outer Mongolia. The Turkic Chinese Church of the East Christian Rabban Bar Sauma was the first diplomat from China to reach the royal courts of Christendom in the West.

Background

Hellenistic Greeks

Before the 13th century AD, instances of Europeans going to China or of Chinese going to Europe were very rare. Euthydemus I, Hellenistic ruler of the Greco-Bactrian Kingdom in Central Asia during the 3rd century BC, led an expedition into the Tarim Basin (modern Xinjiang, China) in search of precious metals.For Strabo's depiction of this event, see . Greek influence as far east as the Tarim Basin at this time also seems to be confirmed by the discovery of the Sampul tapestry, a woolen wall hanging with the painting of a blue-eyed soldier, possibly a Greek, and a prancing centaur, a common Hellenistic motif from Greek mythology. However, it is known that other Indo-European peoples such as the Yuezhi, Saka, and Tocharians inhabited the Tarim Basin before and after it was brought under Han Chinese influence during the reign of Emperor Wu of Han ( BC). Emperor Wu's diplomat Zhang Qian () was sent to forge an alliance with the Yuezhi, a mission that was unsuccessful, but he brought back eyewitness reports of legacies of Hellenistic Greek civilization with his travels to "Dayuan" in the Fergana Valley, with Alexandria Eschate as its capital, and the "Daxia" of Bactria, in what is now Afghanistan and Tajikistan. Later the Han captured Dayuan in the Han-Dayuan war. It has also been suggested that the Terracotta Army (sculptures depicting the armies of Qin Shi Huang, first Emperor of China; dated to ~210 BCE), in the Xi'an region of Shaanxi Province, might be inspired by Hellenistic sculptural art, a hypothesis that has caused some controversy.

At the cemetery in Sampul (Shanpula; 山普拉), ~14 km from Khotan (now in Lop County, Hotan Prefecture, Xinjiang), where the aforementioned Sampul tapestry was found, the local inhabitants buried their dead there from roughly 217 BC to 283 AD. Mitochondrial DNA analysis of the human remains has revealed genetic affinities to peoples from the Caucasus, specifically a maternal lineage linked to Ossetians and Iranians, as well as an Eastern-Mediterranean paternal lineage. Seeming to confirm this link, from historical accounts it is known that Alexander the Great, who married a Sogdian woman from Bactria named Roxana,For another publication calling her "Sogdian", see . encouraged his soldiers and generals to marry local women; consequentially, the later kings of the Seleucid Empire and Greco-Bactrian Kingdom had a mixed Persian-Greek ethnic background.

Ancient Romans

Beginning in the age of Augustus (r. 27 BC – 14 AD), the Romans, including authors such as Pliny the Elder, mentioned contacts with the Seres, whom they identified as the producers of silk from distant East Asia and could have been the Chinese or even any number of middlemen of various ethnic backgrounds along the Silk Road of Central Asia and Northwest China. The Eastern-Han era Chinese general Ban Chao, Protector General of the Western Regions, explored Central Asia and in 97 AD dispatched his envoys Gan Ying to Daqin (i.e. the Roman Empire). Gan was dissuaded by Parthian authorities from venturing further than the "west coast" (possibly the Eastern Mediterranean) although he wrote a detailed report about the Roman Empire, its cities, postal network and consular system of government, and presented this to the Han court.

Subsequently, there was a series of Roman embassies in China lasting from the 2nd to 3rd centuries AD, as recorded in Chinese sources. In 166 AD the Book of Later Han records that Romans reached China from the maritime south and presented gifts to the court of Emperor Huan of Han (r. 146–168 AD), claiming they represented Roman emperor Marcus Aurelius Antoninus (Andun 安敦, r. 161–180 AD). There is speculation that they were Roman merchants instead of official diplomats.

At the very least, archaeological evidence supports the claim in the Weilüe and Book of Liang that Roman merchants were active in Southeast Asia, if not the claim of their embassies arriving in China through Jiaozhi, the Chinese-controlled province of northern Vietnam. Roman golden medallions from the reigns of Antoninus Pius and his adopted son Marcus Aurelius have been found in Oc Eo (in the Mekong Delta, near the modern Ho Chi Minh City), a territory that belonged to the Kingdom of Funan bordering Jiaozhi. Suggestive of even earlier activity is a Republican-era Roman glass bowl unearthed from a Western Han tomb of Guangzhou (on the shores of the South China Sea) dated to the early 1st century BC, in addition to ancient Mediterranean goods found in Thailand, Indonesia, and Malaysia. The Greco-Roman geographer Ptolemy wrote in his Antonine-era Geography that a Greek mariner named Alexander had reached a port city beyond the Golden Chersonese (Malay Peninsula, which Ptolemy named as Kattigara; given the archaeological evidence, this could have been Oc Eo,For further information on the archaeological site at Óc Eo in Vietnam, see: although Ferdinand von Richthofen assumed it was Chinese-controlled Hanoi. cited in cited in Roman coins have been found in China, but far fewer than in India.

It is possible that a group of Greek acrobatic performers, who claimed to be from a place "west of the seas" (i.e. Roman Egypt, which the Book of Later Han related to the "Daqin" empire), were presented by a king of Burma to Emperor An of Han in 120 AD.Ban Gu (班固), Houhanshu (後漢書) (Later Han dynasty annals), chap. 86, "Traditions of the Southern Savages; The South-Western Tribes" (Nanman, Xinanyi zhuan 南蠻西南夷列傳). Liezhuan 76. (Beijing: Zhonghua Shuju 中華書局, 1962–1999), p. 1926. "永初元年," 徼外僬僥種夷陸類等三千餘口舉種内附，献象牙､水牛､封牛。 永寧元年，撣國王雍由調复遣使者詣闕朝賀，献樂及幻人，能變化吐火，自支解，易牛馬頭。又善跳丸， 數乃至千。自言我海西人。海西即大秦也，撣國西南通大秦。明年元會，安帝作變於庭，封雍由調爲漢大 都尉，赐印綬､金銀､彩繒各有差也."A translation of this passage into English, in addition to an explanation of how Greek athletic performers figured prominently in the neighboring Parthian and Kushan Empires of Asia, is offered by : It is known that in both the Parthian Empire and Kushan Empire of Asia, ethnic Greeks continued to be employed as entertainers such as musicians and athletes who engaged in athletic competitions.

Byzantine Empire

Byzantine Greek historian Procopius stated that two Church of the East Christian monks eventually uncovered how silk was made. From this revelation, monks were sent by the Byzantine Emperor Justinian (ruled 527–565) as spies on the Silk Road from Constantinople to China and back to steal the silkworm eggs. This resulted in silk production in the Mediterranean, particularly in Thrace, in northern Greece, and gave the Byzantine Empire a monopoly on silk production in medieval Europe until the loss of its territories in Southern Italy. The Byzantine historian Theophylact Simocatta, writing during the reign of Heraclius (r. 610–641), relayed information about China's geography, including its capital city Khubdan (Old Turkic: Khumdan, i.e. Chang'an) and its ruler Taisson whose name meant "Son of Heaven" (Chinese: 天子 Tianzi, although this could be derived from the name of Emperor Taizong of Tang). Theophylact described accurately how China had been divided, by a border along the Yangzi River, into two warring nations, and how its reunification (under the Sui dynasty of 581–618) had coincided with the reign of the Byzantine emperor Maurice.

The Chinese Old Book of Tang and New Book of Tang mention several embassies made by Fu lin (拂菻; i.e. Byzantium), which they equated with Daqin (i.e. the Roman Empire), beginning in 643 with an embassy sent by the king Boduoli (波多力, i.e. Constans II Pogonatos) to Emperor Taizong of Tang, bearing gifts such as red glass. These histories also provided cursory descriptions of Constantinople, its walls, and how it was besieged by Da shi (大食; the Arabs of the Umayyad Caliphate) and their commander "Mo-yi" (摩拽; i.e. Muawiyah I, governor of Syria before becoming caliph), who forced them to pay tribute. From Chinese records it is known that Michael VII Doukas (Mie li sha ling kai sa 滅力沙靈改撒) of Fu lin dispatched a diplomatic mission to China's Song dynasty that arrived in 1081, during the reign of Emperor Shenzong of Song. Some Chinese during the Song period showed interest in countries to the west, such as the early 13th-century Quanzhou customs inspector Zhao Rugua, who described the ancient Lighthouse of Alexandria in his Zhu fan zhi.

Merchants

According to the 9th-century Book of Roads and Kingdoms by ibn Khordadbeh, China was a destination for Radhanite Jews buying boys, female slaves and eunuchs from Europe. During the subsequent Song period there was also a community of Kaifeng Jews in China. The Spaniard, Benjamin of Tudela (from Navarre) was a 12th-century Jewish traveler whose Travels of Benjamin recorded vivid descriptions of Europe, Asia, and Africa, preceding those of Marco Polo by a hundred years.