In the Catholic Church, being declared a “Servant of God” is the first step to sainthood. Servant-of-God John of Monte Corvino was born in the year 1247 and was military man, a judge and a physician before he became a friar. He preached in Persia (Iran), India and to the court of Kublai Khan, where he began his work in China. John preached against the Nestorian heresy that had been deeply entrenched in Chinese Christian doctrine for over 500 years and converted many people to Christianity.

John built a headquarters in Khanbalik, which is now Beijing, in addition to building two churches. He also translated the Book of Psalms and the New Testament into the Tatar language. John also consecrated seven friars to be bishops of nearby dioceses.

John passed away in 1328, and he was mourned by Christians and non-Christians alike. His burial place became a place of Christian Pilgrimage.