Pei Xiu

Pei Xiu (224–3 April 271), courtesy name Jiyan, was a Chinese cartographer, geographer, politician, and writer of the state of Cao Wei during the late Three Kingdoms period and Jin dynasty of China. He was very much trusted by Sima Zhao, and participated in the suppression of Zhuge Dan's rebellion. Following Sima Yan taking the throne of the newly established Jin dynasty, he and Jia Chong had Cao Huan deprived of his position to accord to the will of heaven. In the year 267, Pei Xiu was appointed as the Minister of Works in the Jin government.^[4][5]

Pei Xiu outlined and analysed the advancements of cartography, surveying and mathematics up until his time.^[6] He criticised earlier Han dynasty maps for their lack of precision and quality when representing scale and measured distances, although 20th century archaeological excavations and findings of maps predating the third century prove otherwise. There is also evidence that Zhang Heng (78–139) was the first to establish the grid reference system in Chinese cartography.