Though Hassan had only seventy men, and not much food to give them, he defended the fortress with great courage till Abu Ali, his Dayi, hastened up in the night time with three hundred men. These, with the seventy of the garrison, attacked the besiegers and dispersed them. Melik Shah who was greatly alarmed by this defeat sent troops from Khorassan against Hussein Kaini, Hassan Sabah’s main agent, who was spreading heresy in the Kuhistan province. Hussein retreated to a castle in Mumin where soon he was besieged and in no less danger than Hassan had been very recently in Alamut. Up to this time Hassan had acted as a political agent and religious nuncio in the name of Mostansir, but now he saw an opportunity for securing power for himself and he did not hesitate. Knowing well that lawlessness of the people brought destruction to the throne, he established a system of religion and politics based upon atheism and absolute freedom of action which became the tenet of the Assassins, known, however, to but few and concealed under the veil of religion. Hassan determined to deliver his first great blow at this juncture and begin his career of surprises. He had resolved to rid himself of opponents unsparingly, and to terrify those of his enemies whom he left living. His first victim was Nizam ul Mulk, his classmate, friend and benefactor, a statesman renowned throughout one half of Asia as chief vizir under three Seljuk Sultans, the first of their dynasty, a man of profound wisdom and keen foresight, whose Treatise on the Principles of Government was written for Melik Shah and adopted as his code. In this code the wise vizir explains in the clearest terms the duties of a sovereign. Melik Shah, the most famous and best of the Seljuk Sultans, died three weeks later (1092). The sudden deaths of these two great men filled Western Asia with terror. The vizir was cut down by Hassan Sabah’s Fedavi, or devoted assistants. Melik Shah died of poison. His loss was greatly lamented for he had ruled with justice and made his country prosperous. He was both a statesman and a warrior. To extend commerce he had built bridges and canals; to ensure the safety of merchants and all who traveled he had made each village and hamlet responsible for the crimes committed within its precincts. In this way the entire population assisted in the suppression of robbery, one of the great evils of that time. Hassan had made a notable beginning—he had alarmed all Asia. What were the doctrines of the Ismailians, used by Hassan Ben Sabah?