William of Modena ( – 31 March 1251), also known as William of Sabina, Guglielmo de Chartreaux, Guglielmo de Savoy, Guillelmus, was an Italian clergyman and papal diplomat. He was frequently appointed a legate, or papal ambassador by the popes Honorius III and Gregory IX, especially in Livonia in the 1220s and in the Prussian questions of the 1240s. Eventually he resigned his see to devote himself to these diplomatic issues. On 28 May 1244 he was created Cardinal-Bishop of Sabina by Pope Innocent IV. For a short time (1219–1222) he served also as Vice-Chancellor of the Holy Roman Church. In Livonia Born in Piedmont and named bishop of Modena in May 1222, William was sent as Papal legate to resolve differences that resulted from the outcome of the Livonian Crusade in Livonia in 1225. The Prince Bishop Albert and the semi-monastic military Order, the Livonian Brothers of the Sword, the Teutonic crusaders and the Russians, all had claims, which were made more difficult by language barriers. William soon earned the confidence of all sides, arranging diplomatic compromises on boundaries, overlapping ecclesiastical and territorial jurisdictions, taxes, coinage, and other subjects, but he could not resolve the basic quarrel: who was to be master in Livonia. William sought to remove Estonia from contention by placing it directly under papal control, appointing his own vice-legate as governor, and by bringing in German knights as vassals. But the vice-legate subsequently turned the land over to the Brothers of the Sword. The Chronicle of Henry of Livonia one of the greatest medieval narratives, was written probably as a report for him, giving him the history of the Church in Livonia up to his time. It relates how in 1226, in another stronghold, called Tarwanpe, William of Modena successfully mediated peace between Germans, Danes and Estonians. Intervention for the Stedingers Upon hearing of the situation in Stedingen, the Teutonic knights asked the Pope to intervene in order to avoid bloodshed. On 18 March 1234, in the letter Grandis et gravis, Gregory ordered his legate in Germany, William of Modena, to mediate the dispute between the Stedinger and the archbishop Gerhard II of Lippe. Since the conflict was not resolved before the spring campaign, either word of the pope's decision did not reach the crusaders in time or the archbishop ignored it. The bishoprics of Prussia question Even while William was negotiating in Livonia, the conflicts