Yahya b. Umm-i-Tuwail and His Position in Shiite History and between Transmitters of Hadith

Although Yahya b. Umm-i-Tuwail has been introduced in traditional and historical sources as the Bab of Shiite Imams, but it is not clear for whom exactly he had been the Bab, Imam Sadjdjad or Imam Baqir, 4th and 5th Shiite Imams? So, this is a matter of deference between Imamiyyah and Nusayriyyah. To solve this problem with a vivid answer, we should at first, study Yahya`s life in History and then, it is necessary to study the traditions transmitted through or by Yahya; contents of these traditions, Yahya`s transmitters and his sources, all are of high importance. By these studies, we will find out the detailed history of Yahya`s life and several dark parts of Shiite history. As a conclusion, we will understand that not only Yahya had been a Bab for Shiite Imams, nor even being a Bab was a historical reality in Imamiyyah, at least in the case of Yahya; this subject is nowadays a matter of discussion in academic societies.