Du You () (735 – December 23, 812), courtesy name Junqing (), formally Duke Anjian of Qi (), was a Chinese historian, military general, and politician. He served as chancellor of the Tang Dynasty. Du was born to an eminent aristocratic family in what is now Xi'an, Shaanxi, almost eighteen years before the abrupt rebellion of An Lushan, and received office for the privilege as administrator of Chi-nan commandery (modernly Licheng District). Robert G. Hoyland considers him a "political thinker on a grand scale," comparable to Ibn Khaldun, but he is most often remembered for his thirty-six year compilation of the Tongdian, a historical encyclopedia of 200 sections (volumes) collecting laws, regulations, and general events from ancient times to his own. While considering Confucian teachings on the relationship between father and son essential, Du stated that he didn't believe that they provided relevant information for government policy. A legal specialist and authority over state finances, he became Commissioner for Public Revenue and Salt and Iron, and has been called a "Legalist" for his appreciation of political planners, dismissal of antiquity and concepts like fate, and strong interest in the Xunzi. John Keay calls him "enamored" of Shang Yang. However, despite expending little effort on rectifying Imperial conduct, along the lines of Xun Kuang he still believed in the possibility of moral transformation, and considers rites essential to government (which in Xun Kuang's view encompass all government regulations and institutions). Du favored the light taxation system of the Confucians and the recommendation system of the Han dynasty as a replacement for the examination system. As a character he has often been regarded as antithetical to the more Confucian Lu Zhi, but in reality they seemed to agree on a number of points and Lu didn't have any problem recommending Du for his abilities. Writing of the Tongdian Du You had been impressed by a 35-volume work by Liu Zhi during Emperor Xuanzong's reign known as the Zhengdian, which was a compendium of philosophies, rites, and principles of governance. However, Du considered the Zhengdian to be incomplete, so he expanded on the coverage of the Zhengdian and added writings about the rites, music, and written works of Emperor Xuanzong's time, into a 200-volume work. In 801, while he was still at Huainan, he had his subordinates carry the work to Chang'an to offer it to Emperor Dezong. Emperor Dezong issued an edict