After the death of Mohammed (632), the followers of his son in law and cousin, Ali Ben Abu-Taleb, demanded that he be named the first Caliph. For them, the succession had to be by blood lineage. They were called in Arabic Shiat Ali, deriving in Shiite. Among the Shiites, there is a unique or centralized leadership function in the person of the IMAM. The Imam is infallible and must be a direct descendant of Mohammed (Hussein, the third Imam, was the son of Ali and Fatima, the daughter of Mohammed). However, because the Imam is concealed, the members of the community are free to govern themselves on earth. Within the Shiite Islam, 12 wise men are elected, called in Arabic Ulemas and in Persian Ayatollahs. At present, the supreme leader of the Shiite, Ali Khamenei, governs Iran and is the successor of Ayatollah Khomeini. Large concentrations of Shiites can be found in the south of Iraq, sponsored by Iran. After the fall of dictator Saddam Hussein (who was Sunni), they have governed Iraq scaring away the Sunni minority. Those who left decided to rebel and joined tribal Islamists creating ISIS. In the south of Lebanon, there are many Shiites, representing at least 30% of the population, although they have their own army which is financed, armed and trained by Iran: Hezbollah. The Shiite country, Iran, with 95% of the Shiite population, instigates risings against the Sunni in several countries, such as their support to the Huti Shiites in Yemen, or instigating the Shiites in Bahrein.
The Shiite theology included five religious principles, three of them similar to the Sunni. The fundamental difference is the Imamah, meaning leadership and guidance, in religious and mundane affairs, following the Prophet of Islam.