Shiʿa Muslims are the followers of Ali (Shiʿat Ali), the cousin and brother-in-law of the prophet Muhammad, to whose descendants they believe
leadership of the entire Muslim community rightfully belongs. Ali ibn Abi Talib succeeded the first three successors of Muhammad, but his rule was contested. The successor to Ali, Muʿawiyya, was succeeded by his son Yazid. The second son of Ali, Husayn, revolted against him and was martyred in 632 c.e.. Although they share with Sunnis the basic tenets of Islam, Shiʿas have different doctrines, rituals, theology, and organization. Shiʿas comprise the smaller of the two major branches of Islam. They are predominant in Iran and a majority in Iraq, but elsewhere in the Muslim world are a minority, making up around 15 percent of the world's Muslim population. They constitute a substantial minority in Kuwait, Bahrain, Saudi Arabia, Yemen, Lebanon, Pakistan, India, and Afghanistan. In many places Shiʿas are subjected by Sunni majorities to discrimination and sometimes violence; in Iraq, where they are a majority, they have been suppressed for political reasons for decades.