The Mongol dynasty's relation to Islam, in particular, had tremendous impact on China's relations with the outside world.
The Mongols recruited a number of Muslims to help in the rule of China, especially in the field of financial administration — Muslims often served as tax collectors and administrators. They were accorded extraordinary opportunities during the Mongol period because Khubilai Khan and the other Mongol rulers of China could not rely exclusively upon the subjugated Chinese to help in ruling China. They needed outsiders, and the Muslims were among those who assisted Khubilai.
The Mongols in China also recognized that Islamic scholars had made great leaps in the studies of astronomy and medicine, and they invited many specialists in those fields to come to China. Among those to make the trip was the Persian astronomer Jamal Al-din, who helped the Chinese set up an observatory. Bringing with him many diagrams and advanced astronomical instruments from Persia, Jamal Al-din assisted the Chinese in developing a new, more accurate calendar.
The Mongols were also impressed by the Persians' advances in medicine. They recruited a number of Persian doctors to China to establish an Office for Muslim Medicine, and the result was even greater contact between West Asia and East Asia.