ISLAM
While the
Sunnis believe that a Caliph should be elected by the community, Shia's believe that
Muhhamad appointed his son-in-law, Ali ibn Abi Talib, as his successor and only certain
descendants of Ali could be Imams(leaders). All in all, they believe that Ali ibn Abi Talib was
the first Imam, rejecting the legitimacy of the previous Muslim caliphs Abu Bakr, Uthman ibn
al-Affan and Umar ibn al-Khattab.
Shia Islam has some several branches. The largest of which is the Twelvers, followed by
Zaidis and Ismailis. Different branches accept different descendants of Ali as Imams. After the
death of Imam Jafar al-Sadiq considered the sixth Imam by the Twelvers, and the Ismaili's,
the Ismailis started to consider his son Isma'il ibn Jafar as the Imam and the Twelver Shia's
started to consider his other son Musa al-Kazim as their seventh Imam. While the Zaydis
consider Zayd ibn Ali, the uncle of Imam Jafar al-Sadiq, as their fifth man.