Du Yan (978-1057), courtesy name Shichang, was a native of Shanyin (now Shaoxing) in the Northern Song Dynasty. He was a Jinshi in the first year of Dazhong Xiangfu. He first served as local officials in Pingyao, Qianzhou and other places, and made great achievements in governance. When he left office, the local people reluctantly sent him to the border. They all said, "How can we take away my good governor?" Later, Dr. Taichang recommended the Hedong Road Prison, and many unjust sentences were redressed. Empress Dowager Zhang Xian said of his political achievements, "I have known about him for a long time." In the fourth year of Qingli (1044), he became prime minister with Tongping Zhangshi, a bachelor of Jixian Hall and a privy envoy. He is an honest official, does not own any private property, lives in a humble house with gauze curtains and quilts, and is respected by others.
  He is good at poetry and has good writing skills in regular, running and cursive writing. Su Shi said: "Zheng Xiangong learned cursive calligraphy in his later years, and became the best of his generation. He was leisurely and beautiful, and gained the style of Jin people."

Du Yan's "Midwinter Severe Cold Notes" on paper, collected by the National Palace Museum, Taipei