Similar to other branches of Islam, Shi'a Islam is based on the teachings of the Islamic holy book, the Qur'an and the message of the final prophet of Islam, Muhammad. In contrast to other branches, Shi'a Islam holds that Muhammad's family, the Ahl al-Bayt ("the People of the House"), and certain individuals among his descendants, who are known as Imams, have special spiritual and political rule over the community. Shia Muslims further believe that Ali, Muhammad's cousin and son-in-law, was the first of these Imams and was the rightful successor to Muhammad and thus reject the legitimacy of the first three Rashidun caliphs. Shī‘ah Muslims, though a minority in the Muslim world, constitute the majority of the populations in Iran, Azerbaijan Bahrain and Iraq. Countries with significant minor