In 1245 Pope Innocent IV sent Father Giovanni da Pian del Carpine (John of Plano Carpini) to an embassy to the court of the Grand Khan of the Mongol Empire in Karakorum Mongolia (Khalkha Mongolian: Хархорин Kharkhorin). One of the first Europeans to enter the court of the Great Khan, Carpine was the author of the earliest important Western account of northern and central Asia, Rus, and other regions of the Mongol dominion, Ystoria Mongalorum.
"He [Carpine] went by Prague and Kiev to Mongolia, where he presented his letter and received his reply. This reply—the original—was discovered by accident in the year 1920 in the archives of the Vatican. It is written in Uigur and Persian and contains in lieu of his signature the seal of the Grand Khan Kouyouk (grandson of Jenghis)[Güyük Khan]. This is the first recorded appearance in Europe of an impression from a seal based on those in use in China and impressed with ink upon paper" (Carter, Invention of Printing in China 2nd ed  159-60).