Muslims claim that in 650 AD, at the age of forty, Muhammad had a visitation from the Angel Gabriel telling him that he had been chosen to learn, recite and spread the words of God to man in verses that would later make up the Qu'ran. He slowly developed into a prophet, preaching monotheism to the masses. He was initially mocked and rejected by many and risked numerous assassination attempts throughout his life. At a critical time, he also made the revolutionary decision to break all ties with his Muslim tribe thereby proclaiming that the bonds of Islam took precedence over anything else. The Islamic empire thus expanded into Palestine, Syria, Mesopotamia, Persia, Egypt, North Africa and Spain. Karen Armstrong has written a account of this figure whose life and influence has determined the course of the spiritual life of human kind.