ammad ibn Ḥ asan Ṭ ū s ī ( Persian : محمدبن محمدبن حسن طوسی ) (born 18 February 1201 in Ṭ ū s , Khorasan – 26 June 1274 in al-K āż imiyyah , Baghdad ), better known as Na ṣ ī r al-D ī n al- Ṭ ū s