The Twelve Imams are the spiritual and political successors to the Islamic prophet Muhammad in the Twelver branch of Shia Islam. According to the theology of Twelvers, the Twelve Imams are infallible human individuals who not only ruled over the community with justice, but also were able to keep and interpret sharia. It is believed by Twelver Shia Muslims that the Twelve Imams were foretold in the Hadith of the Twelve Successors. The Imams were guided by secret texts in their possession, such as al-Jafr and al-Jamia. Ali (calligraphy pictured) was the first of the Twelve Imams, and, in the Twelvers' view, the rightful successor to Muhammad, followed by male descendants of Muhammad through his daughter Fatimah. Each Imam was the son of the previous Imam, with the exception of Husayn ibn Ali, who was the brother of Hasan ibn Ali. The twelfth and final Imam is Muhammad al-Mahdi, who is believed by the Twelvers to be currently alive, and hidden in the Major Occultation until he returns to bring justice to the world. All of the Imams met unnatural deaths, with the exception of the last Imam. (Full list...)