supported in Rome by imperial forces and Italian allies of the emperor, Calixtus II managed to gain the upper hand amid clear demonstrations of popular support. The Imperial candidate was obliged to flee to the fortress of Sutri, where he was taken prisoner through the intervention of Norman support from the Kingdom of Sicily. He was transferred from prison to prison first near Salerno, and afterwards at the fortress of Fumo. The imperial allies in Rome soon disbanded. Sicut Judaeis In 1120 Calixtus II issued the papal bull Sicut Judaeis (Latin: "As the Jews") setting out the official position of the papacy regarding the treatment of Jews. It was prompted by the First Crusade, during which over five thousand Jews were slaughtered in Europe. The bull was intended to protect Jews and echoed the position of Pope Gregory I that Jews were entitled to "enjoy their lawful liberty". The bull forbade Christians, on pain of excommunication, from forcing Jews to convert, from harming them, from taking their property, from disturbing the celebration of their festivals, and from interfering with their cemeteries. It was reaffirmed by popes Alexander III, Celestine III (1191–1198), Innocent III (1199), Honorius III (1216), Gregory IX (1235), Innocent IV (1246), Alexander IV (1255), Urban IV (1262), Gregory X (1272 & 1274), Nicholas III, Martin IV (1281), Honorius IV (1285–1287), Nicholas IV (1288–92), Clement VI (1348), Urban V (1365), Boniface IX (1389), Martin V (1422), and Nicholas V (1447). Concordat of Worms Having established his power in Italy, the pope resolved to re-open negotiations with Henry V on the question of investiture. Henry V was anxious to put an end to a controversy which had reduced imperial authority in Germany — terminally so, as it appeared in the long run. An embassy of three cardinals was sent by Calixtus II to Germany, and negotiations for a permanent settlement of the investiture struggle were begun in October 1121 at Würzburg, where it was agreed that a general truce should be proclaimed in Germany, that the Church should have free use of its possessions, and that the lands of those in rebellion should be restored. These decrees were communicated to Calixtus II, who despatched the legate Lambert to assist at the synod that had been convoked at Worms, where, on 23 September 1122, the agreement known as the Concordat of Worms was concluded. On his side the Emperor abandoned his