and on 29 July 1243, the Bishopric of Prussia was divided into four dioceses: In 1243 the territorial possessions of the Teutonic Knights were divided into the Dioceses of Culm, Pomesania, Ermland, and Samland. Bishopric of Culm Culm, Bishopric of Pomesania Pomesania, Bishopric of Ermland Warmia (Ermland), and Bishopric of Samland Sambia (Samland, now Kaliningrad), under the archbishopric of Riga with Visby as mother city to Riga. Both cities joined the Hanseatic League. Christian received for his decades of apostolic labor the privilege to select for himself any one of the four new episcopal sees, a choice he refused. An embassy to Frederick II In the meantime William had been at Rome. When Celestine IV died after a short reign of sixteen days, the excommunicated Hohenstaufen emperor, Frederick II, was in possession of the Papal States of the Church around Rome and attempted to intimidate the cardinals into electing a pope to his own liking. The cardinals fled to Anagni and cast their votes for Sinibaldo de' Fieschi, who ascended to the papal throne as Innocent IV on 25 June 1243, after an interregnum of more than a year and a half. Innocent IV had previously been a friend of Frederick II. Immediately after the election the emperor sent messengers with congratulations and overtures of peace, which Innocent refused to receive. Two months later he sent emissaries including Peter de Colmieu, Archbishop of Rouen, William of Modena, who had resigned his episcopal office, and Abbot William of St. Facundus as legates to the emperor at Melfi with instructions to ask him to release the prelates whom he had captured while on their way to a council that Gregory IX had intended to hold at Rome and challenge the emperor to make satisfaction for the injuries which he had inflicted upon the Church, which had caused Gregory IX to put him under the ban of excommunication. Should the emperor deny that he had done any wrong to the Church, or even assert the injustice of the Church, the legates were to propose that the decision should be left to a council of kings, prelates, and temporal princes. Frederick entered into an agreement with Innocent on 31 March 1244. He promised to yield to the demands of the Curia in all essential points, to restore the States of the Church, to release the prelates, and to grant amnesty to the allies of