The above quotation is extracted from the book
"The Monks of Kublai Khan, Emperor of China", translated by Sir E. A. Wallis Budge, London 1928. Most of the information on this page about the life of Sawma and Markos is derived from the introductory chapter of this book. An online copy of most of the book (but without its introductory chapter) can be found here:
http://chass.colostate-pueblo.edu/.
After their unsuccessful attempt to travel through Georgia they returned to Baghdad. Markos was then made Metropolitan of Kathay and Wang and given the name Yahbh-Allaha (which means "God gave him"). They decided to return to China, but were unable to proceed beyond the Oxus River because warfare had cut all the caravan routes. They returned to their monastery in Mosul, staying there for about two years. Then Mar Denha died and Markos (as Mar Yahbhallah III) became Patriarch of the Nestorian Church. This took place in the year AD 1280, which would suggest their visit to Ani probably was in 1276 or 1277.
After the death of Abhgha, his son, Arghon, became ruler (1284-1291). The Mongols wanted to capture Syria and Palestine, but realised that they needed military help from the kings of Europe to accomplish this. There was a close relationship between the Mongols and the Nestorian church, so Arghon asked Sawma to head a diplomatic mission to Europe.
His party travelled to Constantinople to ask the Byzantine Emperor Andronicus II for help. After Constantinople they travelled to Italy, landing in Naples. Then they went to Rome. However, Pope Honorus had recently died (in 1287), so they went on to Tuscany and Genoa, and then into France, to Paris. They also had an audience with the king of England, Edward I, possibly at Bordeaux. They then returned to Rome, and met the new Pope, Nicholas IV. Although the diplomatic mission was ultimately unsuccessful, Sawma returned safely to Arghon's court. Sawma died in 1294, and was buried near Baghdad, in the Church of Der ar-Rhomaye.
Sawma wrote a journal, mostly written in Persian, of his life in China and travels across Asia and Europe. Shortly after his death, this material was translated into Syriac. All copies of both the original and the translation were thought lost until a Syriac manuscript of his journal resurfaced in Iran in 1887 and was later translated into English by Wallis Budge.