Shia is one of the two main branches of Islam. It holds that the Islamic prophet Muhammad designated Ali ibn Abi Talib as his successor and the Imam after him. Ali ibn Abi Talib was born at Mecca where his father, Abu Talib, was an uncle of the Prophet. Ali himself was adopted by Mohammad and educated under his care. As a boy, he became the first adherent of the Muhammad. Mohammad some years afterwards gave his daughter Fatima Zahra to marry him. There is no generally accepted opinion about the occurrence of the Shiite current. Some believe that it arose even during the time of the prophet, the second - after his death, others refer the origin of Shiism to the times of Ali, and others - to the period after his murder.