Ali ibn Tawus al-Hilli

Sayyid Raḍī ad-Deen Alī ibn Mūsa ibn Tawūs al-Ḥasanī (Arabic: السيّد رضي الدين عليّ بن موسى بن جعفر بن طاووس الحسني) (1193–1266 AD), commonly known as Sayyed Ibn Tawus (Arabic: سید بن طاووس), was a Twelver Shia Muslim jurist, theologian, historian and astrologer. He was a descendant of Hasan ibn Ali through his father and a descendant of Husain ibn Ali through his mother. It is said that he met the twelfth Shiite imam, Muhammad al-Mahdi, who according to Shiites is living in occultation. He is known for his library and his numerous works which are still available in their original form and help us learn about the interests of Muslim scholars at the end of the Abbasid era.