Giving an example of Hasan's strictness against music, Charles E. Nowell writes in "The Old Man of the Mountain" that, "A man who frivolously disturbed the puritan austerity of Alamut with flute-playing was expelled from the fortress for ever." (cf. "Speculum", vol. xxii, no. 4, 1947, p. 502). He left no male issue behind him, the two sons he had, as referred to above, having been sentenced to death. Juvaini (p. 680) writes that, "Hasan bin Sabbah used to point out to the execution of both his sons as a reason against any one's imagining that he had conducted propaganda on their behalf and had had that object in mind." According to "Unity and Variety in Muslim Civilization" (ed. by G.E. Von Grunebaum, New York, 1956), "The severity of Hasan-i Sabbah against the peccadolloes of his sons is a proof of the moral discipline which reigned at Alamut." He had numerous opportunities to arrogate the powers of religious leadership to himself, but he always made himself sub-servient to the cause of the Imam. Once his few followers wrote up a genealogy for him in the usual elegant style, he, according to Marshall Hodgson in "The Order of Assassins" (Netherland, 1955, p. 51), "said to have thrown it into the water, remarking that he would rather be the Imam's favoured servant than his degenerate son." E.G. Browne also writes in "A Literary History of Persia" (London, 1964, 2nd vol., p. 20) that Hasan had said, "I would rather be the Imam's chosen servant than his unworthy son." In view of Jorunn J. Buckley, "Hasan's followers were called the party of the truthful, adhering to Hasan's total authority as supereme teacher. Of course, this party's real leader was the Imam, hidden to mortal eyes. Hasan did not try to be recognized as the Imam, rather, his role was that of the hujja, who, as noted, demanded full obedience in the occultation period." (vide "Stvdia Islamica," Paris, LX, 1984, p. 141)
. "The use of wine was strickly forbidden to the Ismailis," writes John Malcolm in "The History of Persia" (London, 1815, 1st vol., p. 401)) "and they were enjoyed the most temperate and abstenious habits." Sayed Amir Ali also writes in "The Spirit of Islam" (London, 1955, p. 340) that, "Hasan bin Sabbah himself was a strict observer of all the precepts of religion, and would not allow drunkeness or dancing or music within the circuit of his rule."
According to "Jamiut Tawarikh" (p.134), "The rest of the time until his death, Hasan bin Sabbah passed inside the house, where he lived; he was occupied with reading books, committing the words of dawa to writing, and administrating the affairs of his realm, and he lived an ascetic, abstemious and pious life."
Hasan bin Sabbah took up his residence in the tower of Alamut. His quarters were a bedroom and library. It is said that only two times during his residence did he find time to emerge from his modest lodgings into the open air. Yet it was here, in his modest quarters that he supervised the stern training of his ardent young fidais. Coarsely attired, consuming simple fare, abjuring wine under penalty of death, devoting their lives to the acquisition of the physical and intellectual skills needed for the accomplishment of their missions, these fidais were intensely loyal to him.
Hasan bin Sabbah fell ill in the month of Rabi II, 518/May, 1124. When he felt that the shadows of death were closing upon him, he summoned his lieutenant at Lamasar, Kiya Buzrug Ummid, and designated him as the next ruler of the Nizari Ismaili State. He also appointed three seniors for assisting Kiya Buzrug until such time as the Imam himself came to head his realm. These advisors were Didar Abu Ali Ardistani, Hasan Adam Qasrani and Kiya Ba Jafar (d. 519/1125). Hasan bin Sabbah died towards the end of Rabi II, 518/middle of June, 1124 at the age of 90 years, and ruled the Alamut and other fortresses for 35 years.