Pierre Jartoux (1669–1720), perhaps the most scientifically gifted among the French Jesuit missionaries in China in the seventeenth and eighteenth centuries, has been studied less than others. Only after being assigned relatively low level tasks for 5 years (1702–1706) he became one of the French fathers who mapped the Empire; then (1712–1720) was responsible for uniforming and unifying the regional maps produced. During the last period, he also taught advanced geometry to the Emperor, and was the first to teach some elements of calculus to Chinese students. Finally, he was deeply involved in the quarrel of the rites. Apart from considering such aspects, this paper also raises the question of the extant documentation regarding Jartoux.