Muhammad is the prophet and founder of Islam. Born in Mecca in 570, most of his early life was spent as a merchant. At age 40, he began to have revelations from Allah that became the basis for the Koran and the foundation of Islam. By 630 he had unified most of Arabia under a single religion. As of 2015, there are over 1.8 billion Muslims in the world who profess, "There is no God but Allah, and Muhammad is his prophet."