Muslims believe that Islam is a faith that has always existed and that it was gradually revealed to humanity by a number of prophets, but the final and complete revelation of the faith was made through the Prophet Muhammad in the 7th century CE.
Muhammad was born in Mecca in Saudi Arabia in 570.He was a deeply spiritual man, and often spent time in meditation on Mount Hira.
The traditional story of the Qur'an tells how one night in 610 he was meditating in a cave on the mountain when he was visited by the angel Jibreel who ordered him to recite.
Once Jibreel mentioned the name of Allah, Muhammad began to recite words which he came to believe were the words of God.
Source:
http://www.bbc.co.uk/religion/religions/islam/history/muhammad_1.shtml
