This article examines the life and career of Yan Chenghan (947–1014), a senior eunuch who served Emperor Song Taizong (r. 976–997) and Song Zhenzong (r. 997–1022) in the early Northern Song dynasty. Compared with other senior eunuchs in the same period, Yan did not possess any military talent, although he frequently held offices in military administration. However, he gained the trust of his masters by his remarkable all-round talents such as regulating rivers and watercourses, constructing fields, equine management, and foreign affairs. He was recognized by the Song Emperor Zhenzong as an honest, obedient, and diligent servant even though he was sometimes criticized as a stubborn and somewhat inconsiderate person. It is worthy to note that unlike many of his colleagues, he did not participate in court politics and stayed away from particularly the factional strife among the civilian officials. In fact, Emperor Zhenzong had written a code of ethics for eunuchs and Yan was the one who received it on behalf of his fellow eunuchs. Yan was perceived as the emperor’s model eunuch. Since his contributions to the Song court are generally unknown, this article explores his important achievements so that they may be better understood. From this study, we gain a better appreciation of the Zhenzong emperor’s ability to control his court personnel by supporting good, stable men.