Shiite Islam is one of the two main branches of Islam, the other being Sunni Islam. It originated from a disagreement over the rightful successor to the Prophet Muhammad after his death in 632 CE. Shiites believe that leadership should have stayed within the Prophet's family, specifically with his cousin and son-in-law, Ali. Shiite Muslims make up about 10-15% of the global Muslim population. They are primarily found in countries like Iran, Iraq, and Bahrain. Shiite practices include unique rituals and commemorations, such as the observance of Ashura, which marks the martyrdom of Imam Hussein, the grandson of Muhammad, at the Battle of Karbala.