F. How and where did this particular branch develop?

The Shia are believed to have started as a political party and developed into a religious movement in the Middle East. The origins of Shiism lie in the disagreement about the succession of Muhammad in the 7th century, when the 'Party of Ali' supported the prophet's son-in-law. The First Civil War (656-661 C.E.) cemented the divisions within the Muslim community.