time the Seljuk sultanate of Rûm paid an annual tribute to Alamut, and Majd ad-Din notified the sultan Kayqubad I that henceforth the tribute was to be paid to him. Kayqubad I requested clarification from Hassan III who informed him that the monies had indeed been assigned to Syria. Hassan III died in 1221, likely from poisoning. He was succeeded by his 9-year-old son Imam 'Alā ad-Din Muhammad, known as Muhammad III, and was the penultimate Isma'ili ruler of Alamut before the Mongol conquest. Because of his age, Hassan's vizier served as regent to the young Imam, and put Hassan's wives and sister to death for the suspected poisoning. Muhammad III reversed the Sunni course his father had set, returning to Shi'ite orthodoxy. His attempts to accommodate the advancing Mongols failed. In 1225, Frederick II was Holy Roman Emperor, a position his father Henry VI had held until 1197. He had committed to prosecuting the Sixth Crusade and married the heiress to the Kingdom of Jerusalem, Isabella II. The next year, the once and future king sent envoys to Majd ad-Din with significant gifts for the imam to ensure his safe passage. Khwarezm had collapsed under the Mongols, but many of the Kwarezmians still operated as mercenaries in northern Iraq. Under the pretense that the road to Alamut was unsafe due to these mercenaries, Majd ad-Din kept the gifts for himself, and provided the safe passage. As a precaution, Majd ad-Din informed al-Aziz Muhammad, emir of Aleppo and son of az-Zahir Ghazi, of the emperor's embassy. In the end, Frederick did not complete that trip to the Holy Land due to illness, being excommunicated in 1227. The Knights Hospitaller were not as accommodating as Alamut, demanding their share of the tribute. When Majd ad-Din refused, the Hospitallers attacked and carried off the majority of the booty. Majd ad-Din was succeeded by Sirāj ad-Din Muzaffa ibn al-Husain in 1227, serving as chief da'i until 1239. Taj ad-Din Abu'l-Futūh ibn Muhammad was chief da'i in Syria in 1239, succeeding Sirāj ad-Din Muzaffa. At this point, the Assassins were an integral part of Syrian politics. The Arab historian Ibn Wasil had a friendship with Taj ad-Din and writes of Badr ad-Din, qadi of Sinjar, who sought refuge with Taj ad-Din to escape the wrath of Egyptian Ayyubid ruler as-Salih Ayyub. Taj ad-Din served until at least 1249 when he was replaced by Radi