Although the presence of Nestorian Christianity in China under the Tang dynasty is a familiar enough matter to students of religion, many scholars in Chinese studies were until very recently reluctant to undertake substantial research into this topic, for the very good reason that they had been expecting the appearance of posthumous work on one of our main sources for this episode by Paul Pelliot (1878–1945), who was probably the greatest Asianist of the twentieth century. In 1984 Pelliot's translation of the source in question, the ‘Nestorian stele of Xian’, originally erected in 781 but first rediscovered in the seventeenth century, was actually published as part of a posthumous publication by another scholar, J. Dauvillier, who had been concerned primarily with the Syriac portions of the stele inscription. Since, however, Dauvillier's volume did not include any of Pelliot's copious notes to his translation, sinological scholarship was not substantially advanced by the appearance of this monograph.