Like his brother Mahommed (1104-1118), who successfully rebelled against him, his most dangerous enemies were the Ismailites, who had succeeded in taking the fortress of Alamut (north of Kazvin) and become a formidable political power by the organization of bands of fedais, who were always ready, even at the sacrifice of their own lives, to murder any one whom they were commanded to slay.
Hulagu at Once proceeded to destroy a number of nascent dynasties which endeavoured to establish themselves on the ruins of the Khwarizm Empire; about 1255 he destroyed the dynasty of the i by the capture of their stronghold of Alamut (Eagles Nest), and finally in 1258 captured Bagdad.
Zenos account is that a son named Allamur (called also, Alamut, Alvante, El-wand and Aiwung Bey) was the next king, who, Anaithy besides, Persia, possessed Diarbekr and part of greater Armenia near the Euphrates.
This account is confirmed by Angiolello, a traveller who followed his countrymen Barbaro and Contarini to Persia; and from the two authorities combined may be gathered the further narration of the murder of Rustam and usurpation of the throne by a certain Ahmad, whose death, under torture, six months afterwards, made way for Alamut, the young son of Uasan.
At last a youth named Alamut, aged fourteen years, was raised to the throne, which he held till the succession of Sheikh Ismail.