Twelver Shia, also known as Ithna Ashariyya, is the largest branch of Shia Islam. Followers believe in a line of twelve Imams, spiritual leaders who are considered the rightful successors to the Prophet Muhammad. The first Imam is Ali, the Prophet's cousin and son-in-law, and the twelfth Imam, Muhammad al-Mahdi, is believed to be in occultation and will return as a messianic figure. Twelver Shia theology emphasizes the importance of the Imams as intermediaries between God and humanity. They hold that the Imams possess divine knowledge and authority, guiding the community in spiritual and temporal matters. This belief shapes their practices, rituals, and community structure, distinguishing them from other Islamic sects.