Muhammad is the central prophet of the Islamic faith. Born into a noble Quraish (Quraysh) clan, he was orphaned at an early age. He grew up to be a successful merchant, then turned contemplative; it's said that beginning when he was 40, Muhammad was commanded by Allah (God) to recite the words that would later become Islam's holy book, the Qur'an (or Koran). As the revelations continued, Muhammad preached publicly of the duty to submit to the one true god, gaining followers and earning the enmity of the polytheistic authorities. To escape persecution, Muhammad was forced to flee in 622 to Yathrib (later called Medina). His poetic recitations and pleas for social justice continued to win converts, and Muhammad was repeatedly called into battle in his efforts to unite Arabia behind the faith known as Islam (meaning "submission"). After finally conquering Mecca in 630, Muhammad returned to Medina, where he died in 632.
The prophet's name is sometimes spelled 'Mohammed' or 'Mohamet'... To show respect, many Muslims say or write "peace be upon him" (abbreviated "pbuh") after the name of Muhammad and other prophets... Boxer Cassius Clay took the name Muhammad Ali when he converted to Islam in the 1960s.