ابوعلی حسن بن علی بن اسحاق طوسی شناخته شده به خواجه نظام‌الملک طوسی (۲۸ مهر ۳۹۷ تا ۲۲ مهر ۴۷۱) (متولد ۴۰۸ هـ.ق، طوس، کشته شده در صحنه کرمانشاه به دست یک باطنی ۴۸۵ هـ.ق) وزیر نیرومند دو تن از شاهان بزرگ دوره سلجوقیان، آلپ ارسلان و ملکشاه یکم در ایران بود. خواجه در ۲۱ سالگی با انحطاط سلطنت غزنوی و هجوم ترکمانان سلجوقی به خراسان به خدمت سلجوقیان وارد شد. وی نیرومندترین وزیر در دودمان سلجوقی بود و سلجوقیان نیز در زمان وی به اوج نیرومندی رسیدند. او ۲۹ سال سیاست درونی و بیرونی را رقم می‌زد. وی از بزرگ‌ترین پیشگامان توسعه فرهنگی بعد از حمله اعراب بود و مدارس زیادی به نام نظامیه تأسیس کرد که نظامیه بغداد مهم‌ترین آنها بود Abu Ali al-Hasan al-Tusi Nizam al-Mulk or Khwaja Nizam al-Mulk al-Tusi (خواجه نظام‌الملک طوسی in Persian; 1018 – 14 October 1092) was a celebrated Persian scholar and vizier of the Seljuq Empire. He was also for a short time the sole ruler of the Seljuk Empire. Born in Tus in Persia (Iran), and initially serving the Ghaznavid sultans, Nizam ul-Mulk became chief administrator of the entire Khorasan province by 1059 AD. From 1063, he served the Seljuks as vizier and remained in that position throughout the reigns of Alp Arslan (1063-1072) and Malik Shah I (1072-1092). He left a great impact on organization of the Seljuk governmental bodies and hence the title Nizam al-Mulk which translates as "the order of state". He was pivotal figure who bridged the political gap between both the Abbasids and the Seljuks against their various rivals such as the Fatamids and the Buyids. Aside from his extraordinary influence as vizier with full authority, he is also well-known for systematically founding a number of schools of higher education in several cities, the famous Nizamiyyah schools, which were named after him. In many aspects, these schools turned out to be the predecessors and models of universities that were established in Europe. Nizam ul-Mulk is also widely known for his voluminous treatise on kingship titled Siyasatnama (The Book of Government). He also wrote a book titled Dastur al-Wuzarā, written for his son Abolfath Fakhr-ol-Malek, which is not dissimilar to the famous book of Qabus nama. Nizam ul-Mulk was assassinated en route from Isfahan to Baghdad on the 10th of Ramadhan of 1092 AD. The mainstream literature says he was stabbed by the dagger of a member of the Assassins (Hashshashin) sent by the notorious Hassan-i Sabah near Nahavand, Persia, as he was being carried on his litter. The killer approached him disguised as a dervish.[citation needed] This account is particularly interesting in light of a possibly apocryphal story recounted by Jorge Luis Borges. In this story a pact is formed between a young Nizam ul-Mulk (at that time known as Abdul Khassem) and his two friends, Omar Khayyam and Hassan-i-Sabah. Their agreement stated that if one should rise to prominence, that they would help the other two to do likewise. Nizam ul-Mulk was the first to do this when he was appointed vizier to the sultan Alp Arslan. To fulfil the pact he offered both friends positions of rank within the court. Omar refused the offer, asking instead to be given the means to continue his studies indefinitely. This Nizam did, as well as building him an observatory. Although Hassan, unlike Omar, decided to accept the appointment offered to him, he was forced to flee after plotting to dispose Nizam as vizier. Subsequently, Hassan came upon and conquered the fortress of Alamut, from where he established the Assassins. Another report says he was killed in secret by Malik Shah I in an internal power struggle. Consequently, his murder was avenged by the vizier's loyal academics of the Nizamiyyah, by assassinating the Sultan[3] . The account is disputed and remains a controversy because of the long history of friendship between Malik Shah I and Nizam. Another report says that he was assassinated with Malik Shah I in the same year, after a debate between Sunni and Shi'a scholars which was prepared by him by the orders
