The Rise of Islam

Around 610 a merchant of Mecca, Muhammad, began preaching a new faith. Driven out in 622, he built a community in Medina, and by his death in 632 most of Arabia followed him.

His successors' armies then fell on two exhausted empires. Within twenty years they had taken Syria and Egypt from Byzantium and destroyed Persia entirely.

By 711 the Umayyad caliphs ruled from Spain to the Indus, the largest empire the world had yet seen. Islam and Arabic spread more slowly, over centuries, and a split between Sunni and Shia began after Karbala.