The great man "Nizam al-Mulk," the famous Seljuk vizier. In reality, they were not successful in killing him because he was one of the best men in terms of justice, compassion for scholars, and encouragement of knowledge. He was the one who established the Nizamiyya school in Nishapur and the Nizamiyya school in Baghdad, where Al-Juwayni, Al-Ghazali, Al-Kimiya Al-Khwarizmi, and others like them studied. He embraced the Ash'ari school of thought and helped spread it. This vizier wrote a treatise in Persian on Nizam al-Mulk containing many sound opinions, such as warning the Sultan against the irresponsible interference of his friends in state affairs, and against the interference of some court officials in examining lawsuits, issuing judgments, and exploiting their authority to extort money from the subjects. Finally, Nizam al-Mulk warned the Seljuk Sultan about the Hashshashin and advised him to fight them before their affair escalated. However, they managed to kill Nizam al-Mulk before he could kill them. He had gone out on a journey when a young man from these fedayeen intercepted him, disguised as a Sufi, pretending he wanted to do a good deed. He extended his hand to him, and Nizam al-Mulk extended his hand to him. This young man seized this opportunity and stabbed him with a dagger, from which he died. The amir of this fortress was called Da'i al-Du'at, and below him