Jean-François Gerbillon (4 June 1654, Verdun, France – 27 March 1707, Peking, China) was a French missionary who worked in China. He entered the Society of Jesus, 5 Oct, 1670, and after completing the usual course of study taught grammar and humanities for seven years. His long-cherished desire to labor in the missions of the East was gratified in 1685, when he joined the group of Jesuits who had been chosen to found the French mission in China. For the first leg of the trip, he was attached to the embassy of the Chevalier de Chaumont to Siam, and was accompanied by a group of Jesuit mathematicians (Jean de Fontaney (1643–1710), Joachim Bouvet (1656–1730), Louis Le Comte (1655–1728), Guy Tachard (1648–1712) and Claude de Visdelou (1656–1737)). Tachard would remain in Siam besides King Narai, but the others would reach China in 1687. Upon their arrival in Beijing they were received by the Kangxi Emperor who was favorably impressed by them and retained Gerbillion and Joachim Bouvet at the court. This famous monarch realized the value of the services which the fathers could render to him owing to their scientific attainments, and they on their part were glad in this way to win his favour and gain prestige in order to further the interests of the infant mission. As soon as they had learned the language of the country, Gerbillion with Thomas Pereira, one of his companions, was sent as interpreter to Nerchinsk with the ambassadors commissioned to treat with the Russians regarding the boundaries of the two empires, which were determined in the Treaty of Nerchinsk (1689). This was but the beginning of his travels, during which he was often attached to the suite of the emperor. He made eight different journeys into "Tartary" (i.e., Manchuria and Mongolia). On one of these he was an eyewitness to the campaign in which Kangxi defeated the Oirats. On his last journey he accompanied the three commissioners who regulated public affairs and established new laws among the Khalkha Mongols, who had yielded allegiance to the emperor. He availed himself of this opportunity to determine the latitude and longitude of a number of places in what is today the Northeastern China and adjacent areas of Russia and Mongolia. Gerbillion was for a time in charge of the French college in Beijing, and afterwards became superior-general of the mission. He enjoyed the special friendship and