This fourth chapter provides an extended discussion of the promulgation and surviving manuscript copies of the 1179 conciliar canons. It begins with an analysis of the methods by which the canons of papal councils were promulgated and transmitted between ca. 1050 and 1215, before briefly detailing the events of the 1179 Lateran Council as far as they can be reconstructed from surviving narrative accounts. The majority of the chapter, however, focusses on the dissemination and movement of the 1179 conciliar decrees, and what that can tell us about contemporary perceptions of papal conciliar canons. A key issue is the extent to which the decrees were transmitted as a coherent whole, and therefore viewed as a set of texts that had to be kept together without alteration. Overall, the chapter suggests that the 1179 canons initially existed in more than one recension but, more importantly, demonstrates that the versions that were received in different areas of Christendom were not necessarily the same. It therefore illustrates how uncertain the transmission of papal ‘legislation’ remained, late into the twelfth century.