Semedo, a Jesuit who lived in China for more than 20 years, was the first European scholar to see and translate the Nestorian monument in Xian. This monument demonstrated the presence of Christians in China in the 7th century and helped to legitimize Christianity in the eyes of many Chinese as an Asian religion. A final section on the invasion of the Tartars was written by Martino Martini. Martini, a Jesuit superior in Hangzhou, traveled across China as far as the Great Wall. His survey established a basis for the maps of Cantelli and Coronelli.