Nasir al-Din al-Tusi
Khawaja Muhammad ibn Muhammad ibn Hasan Tūsī (Persian: محمد بن محمد بن الحسن طوسی) (born 17 February 1201 in Ṭūs, Khorasan – died on 25 June 1274 in al-Kāżimiyyah district of metropolitan Baghdad), better known as Nasīr al-Dīn Tūsī (Persian: نصیر الدین طوسی; or simply Tusi in the West), was a Persian[1][2][3][4] polymath and prolific writer: an architect, astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed.[citation needed] He was of the Ismaili-, and subsequently Twelver Shī‘ah Islamic belief.[5] The Muslim scholar Ibn Khaldun (1332–1406) considered Tusi to be the greatest of the later Persian scholars.[6]

Nasir al-Din Tusi was born in the city of Tus in medieval Khorasan (in north-eastern Iran) in the year 1201 and began his studies at an early age. In Hamadan and Tus he studied the Qur'an, Hadith, Shi'a jurisprudence, logic, philosophy, mathematics, medicine and astronomy.[7]
He was apparently born into a Shī‘ah family and lost his father at a young age. Fulfilling the wish of his father, the young Muhammad took learning and scholarship very seriously and travelled far and wide to attend the lectures of renowned scholars and acquire the knowledge which guides people to the happiness of the next world. At a young age he moved to Nishapur to study philosophy under Farid al-Din Damad and mathematics under Muhammad Hasib.[8] He met also Farid al-Din 'Attar, the legendary Sufi master who was later killed by Mongol invaders and attended the lectures of Qutb al-Din al-Misri.
In Mosul he studied mathematics and astronomy with Kamal al-Din Yunus (d. 639/1242). Later on he corresponded with Sadr al-Din al-Qunawi, the son-in-law of Ibn al-'Arabi, and it seems that mysticism, as propagated by Sufi masters of his time, was not appealing to his mind and once the occasion was suitable, he composed his own manual of philosophical Sufism in the form of a small booklet entitled Awsaf al-Ashraf "The Attributes of the Illustrious".
As the armies of Genghis Khan swept his homeland, he was captured by the Ismailis and made his most important contributions in science during this time when he was moving from one stronghold to another. He finally joined Hulagu Khan's ranks, after the invasion of the Alamut castle by the Mongol forces.