Born about 570 CE and died 632 CE, at 25 Mohammad gained financial security by marrying Khadija, a wealthy widow.
In Mecca he received visions and attacked the deities. This upset the leading families because of the threat to business. He had to leave, lost his clan protection and went to Medina.
Within ten years he was political leader of central and western Arabia, and a big military victory over Meccans at Badr in 624 and diplomatic victory in 628 led directly to the peaceful surrender of Mecca to Muhammad in 630.
Caliphs (deputies) emerged after his death, over more and more land, into India but defeated in France in Tours in 732, though they stayed in Spain until removed by force in 1492 CE when Muslims and many Jews had to leave. The Ottoman Turks moved into Eastern Europe in the 1400s. Britain removed the last Moghul Emperor from India in 1858. By 1924 after the First World War and Ataturk the Caliphate was abolished. Islam spread more slowly than the military conquests, and since around 1000 C.E. Islam more generally spread peacefully towards China and South East Asia.
The largest minority are the Shi'ites, the party of Ali (cousin and son in law of Mohammad). They deny that orthodoxy comes from consensus of religious authorities and instead developed the idea of an infallible Imam. A line of descendants followed until the twelfth died or went missing in 878. A collective body of religious scholars has taken charge, caretakers of the Imam who is due to return at the end of time.