Du Cong  Du Cong () (794?-873?), courtesy name Yongyu (), formally the Duke of Bin (), was an official of the Tang dynasty of China, serving two terms as chancellor during the reigns of Emperor Wuzong and Emperor Wuzong's cousin Emperor Yizong. He was traditionally considered a skilled politician who maintained his high position throughout his lengthy career, but not a capable chancellor. Du Cong came from a prominent aristocratic family, with his grandfather Du You having served as a chancellor during the reigns of Emperor Dezong, Emperor Dezong's son Emperor Shunzong, and Emperor Shunzong's son Emperor Xianzong. Du Cong's father Du Shifang () was Du You's second son, and served several terms as minister or regional governor. The famed poet Du Mu was his cousin (son of Du Shifang's brother Du Congyu (). Because Du Cong's heritage, he entered civil service early, and as his third assignment he served as a staff member of the Crown Prince. When the imperial scholar Dugu Yu () offered to resign on account of the fact that his father-in-law Quan Deyu had just been made chancellor, Emperor Xianzong, who was impressed with Dugu's talent, stated, "How is it that Quan Deyu gets a son-in-law like Dugu Yu and I do not?" Therefore, for his own daughters, he turned away from the tradition of selecting their husbands from the households of the nobles and the accomplished generals, instead requesting the officials in charge to select their husbands from scholarly officials whose sons had literary talents. Most of the candidates declined, but Du Cong did not. In 814, Emperor Xianzong therefore had him marry Emperor Xianzong's daughter Princess Qiyang, the oldest daughter of Emperor Xianzong's wife Consort Guo. It was said that Princess Qiyang was humble, unlike many princesses of the day, and, to avoid a situation where her servants would look down on the Du household, she declined to take them with her. Little was known about Du's career the rest of Emperor Xianzong's reign, or the reigns of his son Emperor Muzong and Emperor Muzong's son Emperor Jingzong, other than that he eventually became minister of agriculture (司農卿, "Sinong Qing"). In 832, during the reign of Emperor Jingzong's younger brother Emperor Wenzong, Du Cong was made the mayor of Jingzhao Municipality (京兆, i.e., the region of the Tang capital Chang'an).