Very nice article from the Council of Foreign Relations about the origins of the schism of Sunni and Shia Islam.
The Persians (Safavids) converted to Shia Islam in 1501 A.D. in order to fight the Sunni Ottoman Caliphate. The borders of the time determined today’s distribution of the Sunni Shia population, with Iran, Iraq and Azerbaijan being Shia majority countries, and the rest of the Muslim World being Sunni majority. Bahrain is also a Shia majority country.
As I have said before the Sunni-Shia schism is to a large extent the result of the fight between the Ottomans and the Persians for the fertile lands of Mesopotamia, the lands between the rivers Tiger and Euphrates.
85% Sunni and 15% Shia
Map Ethnic Groups of Iraq Green=Shia Arabs, Yellow=Sunni Arabs and blue=Sunni Kurds (white=desert)
PS The Mughal Empire was a non-Muslim Empire
“The Sunni-Shia Divide”
“This 16th Century Battle Created the Modern Middle East”, August 2014