The first sinologist in the modern sense, the Chinese called him xitai, that is, "master of the Far West". A Jesuit, mathematician and cartographer, he was also the author of books on prayer, arithmetic, mnemonics and the existence of God. His life and work were linked to the great missionary expansion dictated by the policy and the commercial expansion carried out by Spain and Portugal in their opening to the East Indies. During the three decades in which he preached Christianity in China, he was able to enter the circle of Chinese literati and gain the trust of the great figures of the Ming dynasty.