Nasir al-Din al-Tusi
Marja' are the supreme legal authority for Twelvers. Some of the historical and notable scholars include Mulla Sadra, Muhammad Baqir Majlisi, Muhammad ibn Ya'qub al-Kulayni, Al-Shaykh al-Saduq, Al-Shaykh Al-Mufid, Shaykh Tusi, Nasir al-Din al-Tusi, and Al-Hilli.