Xu Guangqi

Xu Guangqi (1562 to 1633), also known by his baptismal name Paul, was a Chinese agronomist, astronomer, mathematician, politician and writer of the late Ming dynasty. Born in Shanghai, then a small walled county seat in Songjiang Prefecture, he met the Italian Jesuit Matteo Ricci in Nanjing in 1600 and collaborated with him in translating Western texts into Chinese, most notably the first part of Euclid Elements, and was baptized a Roman Catholic in 1603. He later worked with the Jesuit Sabatino de Ursis as well. In 1629 the emperor appointed him leader of the Shixian calendar reform, which he undertook with Jesuit help. He wrote the Nong Zheng Quan Shu, a treatise on agriculture, and experimented with Western-style irrigation and with crops such as sweet potatoes and cotton during his retirement from office between 1607 and 1610. He is counted among the Three Pillars of Chinese Catholicism.