Rabban Bar Sauma was a Nestorian monk of the Church of the East faith but later became a diplomat for the same organization. He was born in 1220 in Khanbaligh near Beijing, China. It is debated about his specific origins about whether or not he is from the Turkic Uyghur or from the Ongud (Wanggu in Chinese), which was a tribe of Turkic origin associated with the Mongol castle during the Yuan Dynasty. He was of Nestorian faith from the Church of the East and the religion was locally known as Jingjiao. Bar Sauma became an ascetic monk when he turned 20 and then became a religious teacher for a number of decades.
Around the middle years of his life, Rabban Bar Sauma and Rabban Marcos, one of his young students, set off on a journey from China to the religious center known as Jerusalem.But there were complications on the way to their destination when they neared southern Syria. Warnings of danger forced them to turn to Mongol-controlled Persia, or the Ilkhanate, where they were welcomed with open arms. The Partriach of the Church of the East, Mar Denha I, requested that the two travelling monks visit the court of the Ilkhanate ruler Abaqa to retrieve confirmation papers for Denha’s ordination as Patriarch in 1266. During this respite in their journey, Rabban Marcos became a Nestorian bishop. The Patriarch attempted to send the pair back to China as messengers but it was impossible due to extreme military conflict and they remained in Baghdad. After the Patriarch Mar Denha’s death, Rabban Marcos was chosen to replace him as the Patriarch in 1281. His name was changed to Mar Yaballaha III but that did not stop Rabban Bar Sauma and his student from going to see Abaqa that year. Unfortunately, as they traversed the distance to Maragha to confirm Marcos’ position, the Ilkhanate ruler died. He was succeeded by his son, Arghun Khan, who wanted to form a strategic Franco-Mongul alliance with Christian Europeans. The common enemy that Arghun and the Christian Europeans had were the Muslim Mamluks and he was trying to get the alliance so they could eliminate them. Patriarch Mar Yaballaha, a few years after they met Arghun, suggested that Rabban Bar Sauma be the embassy to the Pope and European monks. He went with no delays or complaints for his faith.
In 1287, the now elderly Bar Sauma, while bearing gifts and letters for the Byzantine emperor, the Pope, and the European Kings, set out for Europe. He traveled with a large number of assistants and a calculated 30 riding animals. They went through Armenia to the Byzantine Empire of Trebizond on the Black Sea. Bar Sauma received audience with Andronicus II Palaeologus in Constantinople where he witnessed the great Hagia Sophia, the Greek orthodox patriarchal basilica, and was thoroughly impressed with its utter magnificence. He then went by boat to Italy and eventually reached Rome to meet with Pope Honorius IV but the Pope had unfortunately passed away. After continuing his journey, he went to Paris, France where he spent one month with King Philip the Fair. The King responded positively to the Mongol embassy and gave him numerous presents and even sent one of his nobleman ( Gobert de Helleville) to accompany the embassy. In Gascony (southern France–belonged to Britain at the time), Bar Sauma met with King Edward I of England who seemed overall happy with the embassy. Unfortunately, King Edward could not join a military alliance with the Mongols due to conflicts in Britain with the Welsh and the Scots. On his return home in 1288, Bar Sauma stopped in Rome to see the new Pope, Nicholas IV, and Nicholas gave him a precious tiara to give to Mar Yaballaha when he reached Baghdad.
Rabban Bar Sauma lived out the rest of his life in Baghdad after he returned from the embassy trip to Europe. He wrote a specific account of his travels during his final years which wasn’t translated to English until 1928 and it was called The Monks of Kublai Khan. Rabban Bar Sauma passed away in 1294 after spending his life traveling and teaching.