to be preached in northern Germany. In June 1233, he granted a plenary indulgence to those who took part. In 1233 Gregory IX established the Papal Inquisition to regularize the prosecution of heresy. The Papal Inquisition was intended to bring order to the haphazard episcopal inquisitions which had been established by Lucius III in 1184. Gregory's aim was to bring order and legality to the process of dealing with heresy, since there had been tendencies by mobs of townspeople to burn alleged heretics without much of a trial. In 1231 Pope Gregory IX appointed a number of Papal Inquisitors (Inquisitores haereticae pravitatis), mostly Dominicans and Franciscans, for the various regions of France, Italy and parts of Germany. Contrary to popular belief, the aim was to introduce due process and objective investigation into the beliefs of those accused to the often erratic and unjust persecution of heresy on the part of local ecclesiastical and secular jurisdictions. Gregory was a remarkably skillful and learned lawyer. He caused to be prepared Nova Compilatio decretalium, which was promulgated in numerous copies in 1234 (first printed at Mainz in 1473). This New Compilation of Decretals was the culmination of a long process of systematising the mass of pronouncements that had accumulated since the Early Middle Ages, a process that had been under way since the first half of the 12th century and had come to fruition in the Decretum, compiled and edited by the papally commissioned legist Gratian and published in 1140. The supplement completed the work, which provided the foundation for papal legal theory. In the 1234 Decretals, he invested the doctrine of perpetua servitus iudaeorum – perpetual servitude of the Jews – with the force of canonical law. According to this, the followers of the Talmud would have to remain in a condition of political servitude until Judgment Day. The doctrine then found its way into the doctrine of servitus camerae imperialis, or servitude immediately subject to the Emperor's authority, promulgated by Frederick II. The Jews were thus suppressed from having direct influence over the political process and the life of Christian states into the 19th century and the rise of liberalism. In 1234, Gregory issued the papal bull Rachel suum videns calling for a new crusade to the Holy Land, leading to the Crusade of 1239. In 1239, under the influence of Nicholas Donin, a Jewish convert to Christianity, Gregory ordered that