The second reason which explains the success of the Moslems in their warfare upon the Christians, had to do with the conduct of those Mohammedan soldiers who went forth to do battle for the true faith. The Prophet promised that those who fell, facing the enemy, would go directly to Heaven. This made sudden death in the field preferable to a long but dreary existence upon this earth. It gave the Mohammedans an enormous advantage over the Crusaders who were in constant dread of a dark hereafter, and who stuck to the good things of this world as long as they possibly could. Incidentally it explains why even to-day Moslem soldiers will charge into the fire of European machine guns quite indifferent to the fate that awaits them and why they are such dangerous and persistent enemies. Having put his religious house in order, Mohammed now began to enjoy his power as the undisputed ruler of a large number of Arab tribes. But success has been the undoing of a large number of men who were great in the days of adversity. He tried to gain the good will of the rich people by a number of regulations which could appeal to those of wealth. He allowed the Faithful to have four wives. As one wife was a costly investment in those olden days when brides were bought directly from the parents, four wives became a positive luxury except to those who possessed camels and dromedaries and date orchards beyond the dreams of avarice. A religion which at first had been meant for the hardy hunters of the high skied desert was gradually transformed to suit the needs of the smug merchants who lived in the bazaars of the cities. It was a regrettable change from the original program and it did very little good to the cause of Mohammedanism. As for the prophet himself, he went on preaching the truth of Allah and proclaiming new rules of conduct until he died, quite suddenly, of a fever on June the seventh of the year 632. His successor as Caliph (or leader) of the Moslems was his father-in-law, Abu-Bekr, who had shared the early dangers of the prophet's life. Two years later, Abu-Bekr died and Omar ibn Al-Khattab followed him. In less than ten years he conquered Egypt, Persia, Phoenicia, Syria and Palestine and made Damascus the capital of the first Mohammedan world empire.