South and East Asians in medieval Europe | AskHistorians Archive Observer

The most famous example is Rabban Bar Sauma. Either a Uyghur or Turkic Mongol*, he was born somewhere near Beijing in c.1220, during the Yuan (Mongol) dynasty. He was an Eastern Rite Christian (generally known to westerners as Nestorians) and became a monk in his 20s. Later, he and one of his students, Rabban Markos, decided to go on pilgrimage to Jerusalem. However, due to wars in the area they ended up stuck in Baghdad. While there, Rabban Bar Sauma's student Rabban Markos was elected Patriarch of the Church of the East. However, this needed approval from Arghun Khan, ruler of the Ilkhanate. Arghun Khan was a Buddhist (though with syncretic elements of Tengriism), but patronised Christians as well. So the pair moved to the court of Arghun Khan.

Arghun Khan wanted to make an alliance with Western European powers against the Mamluk Sultanate. As Patriarch Rabban Markos had become a fairly important man in Arghun Khan's court, he suggested his elderly teacher, Rabban Bar Sauma. As a Christian Monk, he seemed like a good choice as Mongol ambassador, as he'd likely be treated with more respect than a Muslim or Buddhist.

Bar Sauma was sent with a large retinue and several translators, as he did not speak any European languages. He met a variety of European notables; Andronicus II Palaeologus of Byzantium, Charles II of Naples, the Cardinals at Rome (he was supposed to meet the Pope, but the Pope had just died), Philip IV of France, Edward I of England, and then the new Pope Nicholas IV on the way back.

According to Bar Sauma's writings, he was generally treated well. As the ambassador of the Ilkhanate, he was treated with respect, and received many gifts for himself, Patriarch Markos, and Arghun Khan. He also doesn't seem to have been seen as some kind of heretic; Pope Nicholas IV gave him communion and let him celebrate Eastern Rite Mass in Rome. Bar Sauma was impressed with his meetings, and also very impressed by the cathedrals he visited in Rome and Constantinople, like the Hagia Sophia.

Unfortunately, while several monarchs were interested in a joint attack on the Mamluks, and Arghun Khan's offer to give Jerusalem to any European King who could conquer Egypt, internal issues meant the offer of alliance came to naught.

Here is a map of his travels:https://upload.wikimedia.org/wikipedia/commons/thumb/c/c3/VoyagesOfRabbanBarSauma.jpg/800px-VoyagesOfRabbanBarSauma.jpg

As an old man, he retired to found a Church in Azerbaijin, and there he wrote a book detailing his travels, including around Europe.

Here is an English translation of what Bar Sauma wrote (though it's in 3rd person), so you can read it for yourself:

https://archive.org/stream/BudgeMonksKublai/Budge_MonksKublai_djvu.txt

The first half is the translators explanation, you want to skip down to page 52, a bit over halfway.

As you can see, he is generally treated very well, though of course he was an ambassador, so you'd expect that. The only awkward note is that the Catholic Cardinals are really keen on checking his theology, but even that doesn't go too badly; they disagree on whether the Holy Spirit comes from Jesus or the Father, but their difference in belief doesn't lead to any accusations of heresy, etc:" The Cardinals said unto him. Doth the Holy Spirit proceed from the Father or from the Son, or is it separate? RABBAN SAWMA replied, Are the Father, and the Son, and the Spirit associated in the things which appertain to the Nature ( keyana ) or separate? The Cardinals answered, They are associated in the things which concern the Nature ( keyana ) but are separate in respect of individual qualities. RABBAN SAWMA said, What are their individual qualities? The Cardinals replied, Of the Father, the act of begetting: of the Son the being begotten: of the Spirit the going forth (proceeding). RABBAN SAWMA said, Which of Them is the cause of that Other? And the Cardinals replied, The Father is the cause of the Son, and the Son is the cause of the Spirit. RABBAN SAWMA said, If they are coequal in Nature ( keyana ), and in operation, and in power, and in authority (or dominion), and the Three Persons ( kenome ) are One, how is it possible for one of Them to be the cause of the Other? For of necessity the Spirit also must be the cause of some other thing; but the discussion is extraneous to the Confession of faith of wise men. We cannot find a demonstration resembling this statement of yours. For behold, the soul is the cause both of the reasoning power and the act of living, but the reasoning power is not the cause of the act of living. The sphere of the sun is the cause of light and heat, and heat is not the cause of light. Thus we think that which is correct, namely, that the Father is the cause of the Son and the Spirit, and that both the Son and the Spirit are causations of His. Adam begot Seth, and made Eve to proceed [from him], and they are three; because in respect there is absolutely no difference between begetting and making to go forth. Then the Cardinals said unto him. We confess that the Spirit proceedeth from the Father and the Son, but not as we said, for we were only putting thy modesty to the test. And RABBAN SAWMA said, It is not right that to something which is one, two, three, or four causes should be [assigned]; on the contrary 1 do not think that this resembleth our Confession of Faith. Now though the Cardinals restrained his speech by means of very many demonstrations, they held him in high esteem because of his power of argument. Then RABBAN SAWMA said unto them, I have come from remote countries neither to discuss, nor to instruct in matter of the Faith, but I came that I might receive a blessing from MAR PAPA, and from the shrines of the saints and to make known the words of King [ARGHON] and the Catholicus. If it be pleasing in your eyes, let us set aside discussion, and do ye give attention and direct someone to show us the churches here and the shrines of the saints; ye will confer a very great favour on your servant and disciple."