Sunni and Shia Islam

The historical divide of Islam into Sunni, or so-called orthodox Islam, and Shia, was caused more by political dispute over successors than doctrinal differences, although differences gradually assumed theological and metaphysical overtones. Despite the split, within centuries Islam reached far into Africa, eastward to the Indian subcontinent and southeast Asia, as well as northward into Central Asia. This expansion was accomplished by traders and missionaries as much as by conquest.

Sunni constitute 85 percent of the world's Muslims; Shia about 15 percent. Each division has four major Shariah or schools of theological law. The Sunni: Hanafi, dominant in the Arab Middle East, India, Pakistan and Afghanistan; Maleki, in north, central and west Africa and Egypt; Shafii, in east Africa, Indonesia and southeast Asia; Hanbali, in Saudi Arabia. The Shia: Ithna Ashariya or Imami, the state religion in Iran, dominant in Iraq and also found in Afghanistan; Nizari Ismaili, present throughout the Muslim world, including Afghanistan, led by the Aga Khan; Zaidiya, in Yemen; Mutazila, in Syria and Lebanon.