During the middle decades of the thirteenth century, the leadership of the Roman Catholic Church committed itself to a program of extensive missionizing. This chapter examines some of the progress achieved in the decade and a half which elapsed between Friar Paul's confrontation in 1263 and the completion of the Pugio fidei in 1278. What was required in the wake of 1263 was a more wide-ranging collection of rabbinic literature and more rigorous argumentation from that literature. The results, as shown in Pugio fidei, are a copious collection of rabbinic sources, the analysis of a broad range of theological issues, and argumentation far more rigorous and precise than that of Friar Paul. The seriousness of Christian missionizing intentions is reflected in both the extensive effort at refining the argumentation of Friar Paul and in the status of the man who led this effort. Friar Raymond Martin had, by 1263, already been active in the new missionizing campaign for some time.