In 570 A.D., Muhammed was born in Mecca. An orphan by the age of six, he grew up to become a caravan manager and then a merchant in Mecca. Muhammed was unhappy with behavior of the people of Mecca, and often went to the desert to meditate. On one of these retreats, he experienced a vision. This vision led to a series of revelations that became the Koran.
Muhammed returned to Mecca and began to preach. His followers in Mecca were persecuted and in 622, Muhammed and his followers left Mecca in what became known as the "Hegira" or flight, and fled to Medina. In 628, Muhammed returned to Mecca at the head of an army. After his death in 632, his disciples carried on his work.
Muhammed's successor was his father-in-law, Abu-Kabr, who became the first caliph. He and his successors launched a holy war or "jihad" on Arab non-believers and slowly converted most of the Arab world to the new faith, known as Islam. As Islam expanded, a split developed as separate Arab empires developed. But Islam continued to spread, expanding through Egypt, across all of North Africa and finally to Spain. The growth of Islam threatened Constantinople many times. Fears of the infidels led, in part, to the Crusades. By the end of the 14th century, Islam had been forced out of Spain and the Ottoman Empire came into existence. The Ottomans would soon become the dominate Muslim power.