The Head of State of the Holy See Pope Francis, who is on a State Visit in Mongolia, presented to the President of Mongolia Khurelsukh Ukhnaa an official copy of the letter of Guyug Khaan of the Great Mongol State, which is kept in the secret library of the Vatican. The official copy of the letter was made up to the highest quality requirements through use of advanced technology.

In his speech to the public, His Holiness Pope Francis said, that 777 years ago, at the end of August and beginning of September 1246, Pope's envoy priest John of Plano Carpini visited Guyug Khaan, the third Khaan of the Great Mongol State, and handed over the official letter of Pope Innocent IV. Soon after, the Great Khaan sent a reply letter with a seal engraved in Mongolian script, translated into many languages, which is now kept in the Vatican Library. “Today, I am respectfully presenting as a gift an official copy of this letter, made in the highest quality using advanced technology. This gift should become a symbol of the ancient friendship relations that are expanding nowadays.”

Clarification:

The Pope's emissary, Monk Plano Carpini, was one of the observers who witnessed the enthronement ceremony of the third Khaan of the Great Mongol State, Guyug, which took place in the Yellow Palace near Kharkhorin. In the fall of 1246, he presented a letter from the Pope to Guyug Khaan, demanding that the Mongols convert to the Crusader religion and confess their guilt for invading the Crusader countries such as Magyar. Consequently, Guyug Khaan not only rejected the Pope's demands and refused to convert to the Crusader religion, but the messenger returned with a letter warning the Pope to come and submit in person. Plano Carpini wrote about this in his travelogue "History of the Mongols". It is believed that Guyug Khaan's letter to the Pope had versions written in Mongolian, Persian, and Latin. In 1920, the Polish priest Krill Karalewski found a Persian letter from the Vatican archives and gave it to the researcher Masse. Masse made the first translation of the letter. Subsequently, a famous French Mongolist P. Pelliot researched and translated this letter. He published it with the Persian original, translation, and commentary and put it into research circulation.

The letter of Guyug Khaan, one meter twelve cm long, 20 meters wide, written in Persian on tarmac paper is stored in the secret archives of the Vatican, This letter, confirmed by double-stamping with the seal of Guyug Khaan of the Great Mongol State at the junction of the paper and at the end of the inscription, is a witness of 777-year history of relations between Mongolia and the Holy See, and a unique valuable heritage.

During his visit to the Vatican City in 2011, the President of Mongolia Elbegdorj Tsakhia got acquainted with valuable heritage related to the history of Mongolia, such as the letter of Guyug Khaan.